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Donger
03-24-2008, 12:22 PM
http://www.cnn.com/2008/LIVING/personal/03/24/gas.tips/index.html

Thought I'd share this one:

(CNN) -- It's costing us more and more money to fill up the gas tank. And while that's unlikely to change anytime soon, there are some tricks to getting the most value per gas dollar.

With gas hitting record highs, people are doing anything they can to ease the pain at the pump.

"People are scared. It's hitting them right in the wallet," says Jason Toews, co-founder of gasbuddy.com, an online gasoline information site. "A number of people tell me their gas bill is more than their car payment. That's a foreign concept to a lot of folks."

Gasoline hit a record $3.28 a gallon last Sunday. Drivers in California pay more than $3.63 a gallon on average, and motorists in Alaska, Oregon, Washington and Hawaii on average all pay more than $3.40 a gallon.

But there are some things you can do to get the most out of the gas in your car's tank.

Find the cheapest gas stations in your area

"In most cities you can save between ten to fifteen cents a gallon by just knowing where to look," says Toews.

The difference between the most expensive gas station and the cheapest gas station is thirty to forty cents on average, according to Toews. Check out our hours for gallons calculator.

Here are some general rules of thumb:

The richest areas of town often charge more for gas.

Gas stations near major highways often charge more for gas because land is generally more valuable in these locations, increasing overhead. Those higher costs are passed onto consumers. So before a road trip, fill up at your local station.

If you must fill up near the highway, try stations near state border lines which tend to price their gasoline aggresively, according to GasPriceWatch.com, a gasoline information Web site.

The type of gas station makes a difference

Service stations with auto repair shops or car washes often have more expensive gas, said Toews. They don't need to be as competitive since they profit more from the other services and rely on them to bring in gas business as well.

You may also find good deals at gas stations affiliated with wholesale clubs. These retailers often sell cheaper gas as a way to get people in the door to buy their other products.

But bear in mind you may have to pay for a membership. Even if you don't want to join a wholesale club, you may want to check out other gas stations in the area. Sometimes the low gas prices these wholesale clubs offer force other stations in the area to be more competitive.

What time you get to the pump

Wednesday morning is the best time to buy gasoline according to GasPriceWatch.com. That's because prices usually move up for the weekend, after which they settle, hitting the low point by Wednesday.

And it makes sense to buy your gas in the morning when it's the coolest time of day. This is when gasoline is most dense. Gas pumps charge by the volume of gasoline, not the density, so in colder temperatures you'll get more for your dollar.

Driving style

Changing from an aggressive hard accelerating, hard braking, driving style to a more relaxed style incorporating gentle acceleration and cruise control on the highway, can improve fuel efficiency by as much as 35 percent, according to an Edmunds.com study.

A scan gauge can help determine the fuel efficiency of your car, according to Phillip Reed of Edmunds.com.

The device plugs into your steering column and helps you keep track of your fuel efficiency at any one moment. A scan gauge isn't cheap. It may cost you $150 or more. Check your local auto parts store or go online to find out more about these devices.

"If you knew that flooring it cost you 50 cents, would you do that? Is it worth it?" asks Reed. "If you knew that one acceleration could cost you 25 cents -- that could change your behavior."

Air cents

Think about your own car's aerodynamics. Even an empty roof rack creates drag. Loaded with luggage, skis or a cooler, a roof rack can reduce fuel economy by 21 percent, says Reed.

There's been a lot of debate about whether keeping the windows open or turning on the air conditioning saves more fuel.

According to Reed, air conditioning is more efficient at highway speeds, while windows are generally better around town at local speeds.

Use the right gas

Regular octane works just fine for most cars. However, when your car's manufacturer indicates premium gas is required, using a lower grade could damage your car, adversely affecting fuel efficiency.

But when premium gas is only recommended, not required, go for the cheaper, lower octane gas, says Reed.

Higher octane gas has only a marginal effect on performance, usually in the area of acceleration, according to Reed.

Bugeater
03-24-2008, 12:31 PM
Service stations with auto repair shops or car washes often have more expensive gas

That ain't no shit, there's a car wash down the street from me with gas pumps and they're always 10-15 cents higher than everywhere else. It sucks because it's would be a convenient place for me to go otherwise.

The "driving style" part is one that many can't seem to comprehend. The other day I was driving in the left lane of a major street and a guy in a full size Ford pickup was tailgating me, and eventually blew around me in the right lane, then got back in front of me only to jump into a left turn lane right away, where I passed him while he waited to make his left turn...wtf?

Bugeater
03-24-2008, 12:38 PM
BTW, I received an email the other day that contained the following information:

When you're filling up do not squeeze the trigger of the nozzle to a fast mode. If you look you will see that the trigger has three (3)stages: low, middle, and high. In slow mode you should be pumping on low speed, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some other liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.

One of the most important tips is to fill up when your gas tank is HALF FULL or HALF EMPTY. The reason for this is, the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine.

Any truth to these items Donger?

Donger
03-24-2008, 12:45 PM
BTW, I received an email the other day that contained the following information:

When you're filling up do not squeeze the trigger of the nozzle to a fast mode. If you look you will see that the trigger has three (3)stages: low, middle, and high. In slow mode you should be pumping on low speed, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some other liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.

One of the most important tips is to fill up when your gas tank is HALF FULL or HALF EMPTY. The reason for this is, the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine.

Any truth to these items Donger?

Minimal benefit, at best. However, it's more fuel efficient to drive around with an almost empty tank anyway.

MIAdragon
03-24-2008, 12:47 PM
http://www.bicyclebuys.com/productimages/BHCAULFSAPART.jpg

Bugeater
03-24-2008, 12:50 PM
http://www.bicyclebuys.com/productimages/BHCAULFSAPART.jpg

Not going to get very far on that without any pedals.

Donger
03-24-2008, 12:52 PM
That 35% number is amazing. I'd imagine it's pretty enthusiastic, but regardless, imagine if everyone in our country started driving that way...

Deberg_1990
03-24-2008, 12:54 PM
Alot of that stuff is just common sense stuff that most people already know, but just are not willing to change.

I still see people everywhere driving the gus guzzling SUV's, but thats in Texas. Might be different in other parts of the country.

MIAdragon
03-24-2008, 12:55 PM
Not going to get very far on that without any pedals.


Its one of those "No effort" down hill kind of bikes.

(nice catch btw)

Brock
03-24-2008, 12:56 PM
A scan gauge can help determine the fuel efficiency of your car, according to Phillip Reed of Edmunds.com.

The device plugs into your steering column and helps you keep track of your fuel efficiency at any one moment. A scan gauge isn't cheap. It may cost you $150 or more. Check your local auto parts store or go online to find out more about these devices.



They still sell one of these in JC Whitney. It's called a vacuum gauge. It costs 25 dollars.

Delano
03-24-2008, 12:56 PM
Yes.

bowener
03-24-2008, 12:56 PM
http://www.bicyclebuys.com/productimages/BHCAULFSAPART.jpg

Apply this gadget (http://www.engadget.com/2006/05/10/the-wheel-turns-your-bike-into-a-moped/) to the above shown object.

$400 is steep for me right now (poor college student), but 240 mpg is nice, especially since I live about 2 miles from campus and every other day I am forced to drive my car to the hearnes parking lot so I can make it to work after class on time.

edit: for those familiar with the layout of columbia; I live south of the stadiums and for me to ride to school I would have to ride up the providence road hill (with heavy traffic).

Fish
03-24-2008, 12:58 PM
BTW, I received an email the other day that contained the following information:

When you're filling up do not squeeze the trigger of the nozzle to a fast mode. If you look you will see that the trigger has three (3)stages: low, middle, and high. In slow mode you should be pumping on low speed, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some other liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.

One of the most important tips is to fill up when your gas tank is HALF FULL or HALF EMPTY. The reason for this is, the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine.

Any truth to these items Donger?

A friend of mine responded to that question on another forum with this...

I love the post, hell I traded in Big Papa for The Kia to save $ on gas - mission accomplished! However I hope everyone realizes that the temperature difference in a 5000 gallon (give or take, i don't know how much they actually hold) UNDERGROUND tank over 12 hours is pretty much ZERO. The temp of the hose between the pump and your gas tank would have more of and effect for about 12 seconds. I have a 100 gallon above ground tank I manage at work and when the cap gets put on wrong (tank not vented) there is a nice surge of air that comes out in the afternoon, but at best I guesstimate it at less than 1/2 pint. Moral of story: Fill-rate is neglagible. But fill up in the evening while the sun is down. The ozone level will thank you.

Bugeater
03-24-2008, 01:01 PM
That 35% number is amazing. I'd imagine it's pretty enthusiastic, but regardless, imagine if everyone in our country started driving that way...
What gets me is it seems the people (like the guy I described earlier) driving the most aggressively are usually driving the most inefficient vehicles as well. They're probably also the ones who complain the loudest about the price of gas.

Bugeater
03-24-2008, 01:02 PM
A friend of mine responded to that question on another forum with this...
I wondered about that when I first heard the temperature theory as underground temps don't vary much.

seclark
03-24-2008, 01:05 PM
bought a harley saturday.
sec

HemiEd
03-24-2008, 01:18 PM
What gets me is it seems the people (like the guy I described earlier) driving the most aggressively are usually driving the most inefficient vehicles as well. They're probably also the ones who complain the loudest about the price of gas.

yeah, I just had one of those guys at lunch. He was driving a v8 Dodge pickup, and kept stomping on it. Funny thing, we stayed very close for many lights, but he was setting there waiting on me to catch up.

In the spirit of this thread, I personally need to eliminate wasted trips in the car. That 1 hour round trip I took at lunch, was to a closed tag office. They are having an Easter holiday today. It is going to be hard for some of us to reprogram ourselves. The part that really pisses me off, it is to correct an error on their part.

HemiEd
03-24-2008, 01:19 PM
bought a harley saturday.
sec

Congrats! thats great!

Frazod
03-24-2008, 01:26 PM
I saw a commercial a couple of weeks ago for some sort of ceramic oil additive that supposedly eliminates most friction, thereby dramatically increasing engine efficiency and mileage. Sounds like some too-good-to-be-true ripoff, but has anybody heard about this? Sure would be nice if it was true. My Impala's fuel economy, especially around town, could best be described as dismal.

DaFace
03-24-2008, 01:28 PM
That 35% number is amazing. I'd imagine it's pretty enthusiastic, but regardless, imagine if everyone in our country started driving that way...

This reminds me of an article I read about home electric usage. Xcel Energy is running a test in Boulder where people are charged a rate based on the load level of the energy grid, so all the participants are given a little box that tells them on-the-fly how much their electricity is costing them. For example, in the middle of a hot summer day, the rate goes up since everyone's using their air conditioners. The idea is that, if you give people more information about how their actions affect their expenses, they will adjust their behavior appropriately to cut down on their costs.

I'll be interested to see if it works, and I'd wonder if having a little "instant usage" monitor on a car would alter people's driving habits.

Silock
03-24-2008, 01:34 PM
I saw a commercial a couple of weeks ago for some sort of ceramic oil additive that supposedly eliminates most friction, thereby dramatically increasing engine efficiency and mileage. Sounds like some too-good-to-be-true ripoff, but has anybody heard about this? Sure would be nice if it was true. My Impala's fuel economy, especially around town, could best be described as dismal.

Ripoff.

Silock
03-24-2008, 01:35 PM
BTW, this thread makes me happy that I have a car that gets a combined 34 mpg and still runs 13s.

elvomito
03-24-2008, 01:35 PM
ever known anyone to use a hydrogen generator to supplement their air intake?
http://search.ebay.com/search/search.dll?sofocus=so&sbrftog=1&dfsp=1&from=R40&_trksid=m37&satitle=hydrogen+gen*&sacat=-1%26catref%3DC6&sargn=-1%26saslc%3D2&sadis=200&fpos=95125&sabfmts=1&sacqyop=ge&sacqy=&ftrt=1&ftrv=1&fbd=1&sabdlo=1&sabdhi=&saprclo=&saprchi=&fsop=34%26fsoo%3D2&coaction=compare&copagenum=1&coentrypage=search&fgtp=

i'd like to know if they work, pretty simple to build.
i read of a shop that was installing them but I've forgotten the details.

KCChiefsMan
03-24-2008, 01:46 PM
I think everybody in Oklahoma must save a shit ton of gas because they all go about 40 on the highways.

Mr. Flopnuts
03-24-2008, 01:47 PM
Alot of that stuff is just common sense stuff that most people already know, but just are not willing to change.

I still see people everywhere driving the gus guzzling SUV's, but thats in Texas. Might be different in other parts of the country.

I have one, and I'm looking to get rid of it this week. We spend $1000 a month to drive between car payments, insurance, and gasoline. The buck stops here.

MIAdragon
03-24-2008, 02:03 PM
BTW, this thread makes me happy that I have a car that gets a combined 34 mpg and still runs 13s.

Heh I was thinking the same thing, I run DEEP into the 11's and still knock down 20+ mpg gotta love modern Tech

Bugeater
03-24-2008, 02:04 PM
I'll be interested to see if it works, and I'd wonder if having a little "instant usage" monitor on a car would alter people's driving habits.
I've seen cars with such a device, IIRC they were on some high end Cadillacs. The problem is that people who buy those cars are either (a) wealthy and less likely to give a damn about gas mileage or (b) 175 yrs old and never exceed 30 mph anyway.

Donger
03-24-2008, 02:11 PM
I've seen cars with such a device, IIRC they were on some high end Cadillacs. The problem is that people who buy those cars are either (a) wealthy and less likely to give a damn about gas mileage or (b) 175 yrs old and never exceed 30 mph anyway.

It's just an OBDII tool. I run the software on my laptop and just plug into the OBD port.

Here's anotehr option: http://www.scangauge.com/

Frazod
03-24-2008, 02:13 PM
Ripoff.

Figured as much.

Donger
03-24-2008, 02:23 PM
ever known anyone to use a hydrogen generator to supplement their air intake?
http://search.ebay.com/search/search.dll?sofocus=so&sbrftog=1&dfsp=1&from=R40&_trksid=m37&satitle=hydrogen+gen*&sacat=-1%26catref%3DC6&sargn=-1%26saslc%3D2&sadis=200&fpos=95125&sabfmts=1&sacqyop=ge&sacqy=&ftrt=1&ftrv=1&fbd=1&sabdlo=1&sabdhi=&saprclo=&saprchi=&fsop=34%26fsoo%3D2&coaction=compare&copagenum=1&coentrypage=search&fgtp=

i'd like to know if they work, pretty simple to build.
i read of a shop that was installing them but I've forgotten the details.

:spock:

elvomito
03-24-2008, 02:26 PM
:spock:you don't think adding a little hydrogen might improve economy?

jAZ
03-24-2008, 02:30 PM
[Use the right gas

Regular octane works just fine for most cars. However, when your car's manufacturer indicates premium gas is required, using a lower grade could damage your car, adversely affecting fuel efficiency.

But when premium gas is only recommended, not required, go for the cheaper, lower octane gas, says Reed.

Higher octane gas has only a marginal effect on performance, usually in the area of acceleration, according to Reed.
Why hasn't the notion of regulating a single octane ever been raised. Seems like streamlining the number of formulations would go a long way towards solving a number of things that go into inflating the price of fuel.

Donger
03-24-2008, 02:32 PM
you don't think adding a little hydrogen might improve economy?

How is the hydrogen generated?

Guru
03-24-2008, 02:32 PM
I still hear that "you get what you pay for" even on gas. I generally go for the happy medium. Not the cheapest but not the most expensive. I do go for name brand right now though. Stopped using BP and am using Phillips 66 at the moment.

Silock
03-24-2008, 02:33 PM
I still hear that "you get what you pay for" even on gas. I generally go for the happy medium. Not the cheapest but not the most expensive. I do go for name brand right now though. Stopped using BP and am using Phillips 66 at the moment.

BP IS name brand.

Donger
03-24-2008, 02:35 PM
Why hasn't the notion of regulating a single octane ever been raised. Seems like streamlining the number of formulations would go a long way towards solving a number of things that go into inflating the price of fuel.

IIRC, it goes back to the 1920s when pre-ignition first came up with ICEs.

Guru
03-24-2008, 02:35 PM
BP IS name brand.

I switched from that because I felt my mileage was suffering though. My mileage has really dipped using their gas over the last 8 months.

Figure I will try P66 first and then try Shell. If I see no difference then I will probably go back to BP since they are the most convenient.

elvomito
03-24-2008, 02:45 PM
How is the hydrogen generated?electrodes are placed in water with sulfuric(battery) acid in it, and current is run through it. a tube runs from the water chamber into the air intake.

Donger
03-24-2008, 02:47 PM
electrodes are placed in water with sulfuric(battery) acid in it, and current is run through it. a tube runs from the water chamber into the air intake.

And how is the current generated?

elvomito
03-24-2008, 02:49 PM
And how is the current generated?from your vehicle's alternator

Donger
03-24-2008, 02:50 PM
from your vehicle's alternator

And what spins the alternator?

Stewie
03-24-2008, 02:55 PM
Donger, don't be mean. Lots of people believe in HHO and those snake oil salesmen will gladly take their money.

elvomito
03-24-2008, 02:55 PM
And what spins the alternator?
a gerbil
the gerbil eats sugary grains
the grains are grown on a farm
a farm that once grew corn but is now subsidized

therefore hydrogen is causing the price of milk and eggs to rise :cuss:

Donger
03-24-2008, 02:56 PM
Donger, don't be mean. Lots of people believe in HHO and those snake oil salesmen will gladly take their money.

I'm not being mean. Many people don't realize that the electrical system in their cars are powered by the ICE.

Donger
03-24-2008, 02:56 PM
a gerbil
the gerbil eats sugary grains
the grains are grown on a farm
a farm that once grew corn but is now subsidized

therefore hydrogen is causing the price of milk and eggs to rise :cuss:

ROFL

chasedude
03-24-2008, 03:00 PM
electrodes are placed in water with sulfuric(battery) acid in it, and current is run through it. a tube runs from the water chamber into the air intake.

Kind of like this?

http://www.chiefsplanet.com/BB/showthread.php?t=174887

http://www.water-4-fuel.com/

DaFace
03-24-2008, 03:21 PM
It's just an OBDII tool. I run the software on my laptop and just plug into the OBD port.

Here's anotehr option: http://www.scangauge.com/

Neat. I want one. But I don't care enough to pay $160 for it, unfortunately.

Donger
03-24-2008, 03:34 PM
Neat. I want one. But I don't care enough to pay $160 for it, unfortunately.

Yeah, I paid something like $60 for the software and the serial cable, mostly so I can clear "Check Engine Light" stuff. It's already paid for itself.

elvomito
03-24-2008, 03:38 PM
I'm not being mean. Many people don't realize that the electrical system in their cars are powered by the ICE.are you implying that using more amps will cause the engine to use more gasoline?

Kind of like this?

http://www.water-4-fuel.com/ROFLROFL wow, what a load of crap.

Silock
03-24-2008, 03:53 PM
I switched from that because I felt my mileage was suffering though. My mileage has really dipped using their gas over the last 8 months.

Figure I will try P66 first and then try Shell. If I see no difference then I will probably go back to BP since they are the most convenient.

I'm just saying. British Petroleum is one of the largest oil companies in the world. They owned Amoco, which used to be popular around here. Then they got rid of the Amoco brand and went straight to BP. In the south, BP is EVERYWHERE and you'll rarely find a Philips 66. It's weird.

EDIT: And it's very possible that you are getting worse gas mileage with them, depending on their ethanol content. Many cars get much worse gas mileage with higher ethanol in the gas.

markk
03-24-2008, 03:57 PM
all i could see on that website were prices from 3.04 to 2.99. 5 cents a gallon is only going to save me about a dollar a tank and that is if i dont have to drive out of my way to get the cheapest price.

best advice is to combine trips and take it easy on the gas pedal in my opinion.

Donger
03-24-2008, 04:15 PM
are you implying that using more amps will cause the engine to use more gasoline?

Yes.

elvomito
03-24-2008, 04:44 PM
Yes.if that were true, then running large amps would definately kill gpm wouldn't you say? it never did for me. besides, at running speeds, the car isn't using that entire 60/90/130amps its generating.
anyway, i suppose supplementing H would be no better than NG would. you'd need fairly large amounts i suppose.

Donger
03-24-2008, 04:48 PM
if that were true, then running large amps would definately kill gpm wouldn't you say? it never did for me. besides, at running speeds, the car isn't using that entire 60/90/130amps its generating.
anyway, i suppose supplementing H would be no better than NG would. you'd need fairly large amounts i suppose.

Perhaps I'm missing something, but I don't see how adding another process, which requires energy derived from the gasoline being burned, increases overall fuel efficiency.

Jenson71
03-24-2008, 04:59 PM
Where's the "Shift your car to neutral going downhill but don't go too far and shift to reverse" suggestion?

Brock
03-24-2008, 05:21 PM
Perhaps I'm missing something, but I don't see how adding another process, which requires energy derived from the gasoline being burned, increases overall fuel efficiency.

Your alternator will be turning anyway. It wouldn't require any more energy than is being used already.

tiptap
03-24-2008, 05:23 PM
http://www.cnn.com/2008/LIVING/personal/03/24/gas.tips/index.html

Thought I'd share this one:

(CNN) -- It's costing us more and more money to fill up the gas tank. And while that's unlikely to change anytime soon, there are some tricks to getting the most value per gas dollar.

With gas hitting record highs, people are doing anything they can to ease the pain at the pump.

"People are scared. It's hitting them right in the wallet," says Jason Toews, co-founder of gasbuddy.com, an online gasoline information site. "A number of people tell me their gas bill is more than their car payment. That's a foreign concept to a lot of folks."

Gasoline hit a record $3.28 a gallon last Sunday. Drivers in California pay more than $3.63 a gallon on average, and motorists in Alaska, Oregon, Washington and Hawaii on average all pay more than $3.40 a gallon.

But there are some things you can do to get the most out of the gas in your car's tank.

Find the cheapest gas stations in your area

"In most cities you can save between ten to fifteen cents a gallon by just knowing where to look," says Toews.

The difference between the most expensive gas station and the cheapest gas station is thirty to forty cents on average, according to Toews. Check out our hours for gallons calculator.

Here are some general rules of thumb:

The richest areas of town often charge more for gas.

Gas stations near major highways often charge more for gas because land is generally more valuable in these locations, increasing overhead. Those higher costs are passed onto consumers. So before a road trip, fill up at your local station.

If you must fill up near the highway, try stations near state border lines which tend to price their gasoline aggresively, according to GasPriceWatch.com, a gasoline information Web site.

The type of gas station makes a difference

Service stations with auto repair shops or car washes often have more expensive gas, said Toews. They don't need to be as competitive since they profit more from the other services and rely on them to bring in gas business as well.

You may also find good deals at gas stations affiliated with wholesale clubs. These retailers often sell cheaper gas as a way to get people in the door to buy their other products.

But bear in mind you may have to pay for a membership. Even if you don't want to join a wholesale club, you may want to check out other gas stations in the area. Sometimes the low gas prices these wholesale clubs offer force other stations in the area to be more competitive.

What time you get to the pump

Wednesday morning is the best time to buy gasoline according to GasPriceWatch.com. That's because prices usually move up for the weekend, after which they settle, hitting the low point by Wednesday.

And it makes sense to buy your gas in the morning when it's the coolest time of day. This is when gasoline is most dense. Gas pumps charge by the volume of gasoline, not the density, so in colder temperatures you'll get more for your dollar.

Driving style

Changing from an aggressive hard accelerating, hard braking, driving style to a more relaxed style incorporating gentle acceleration and cruise control on the highway, can improve fuel efficiency by as much as 35 percent, according to an Edmunds.com study.

A scan gauge can help determine the fuel efficiency of your car, according to Phillip Reed of Edmunds.com.

The device plugs into your steering column and helps you keep track of your fuel efficiency at any one moment. A scan gauge isn't cheap. It may cost you $150 or more. Check your local auto parts store or go online to find out more about these devices.

"If you knew that flooring it cost you 50 cents, would you do that? Is it worth it?" asks Reed. "If you knew that one acceleration could cost you 25 cents -- that could change your behavior."

Air cents

Think about your own car's aerodynamics. Even an empty roof rack creates drag. Loaded with luggage, skis or a cooler, a roof rack can reduce fuel economy by 21 percent, says Reed.

There's been a lot of debate about whether keeping the windows open or turning on the air conditioning saves more fuel.

According to Reed, air conditioning is more efficient at highway speeds, while windows are generally better around town at local speeds.

Use the right gas

Regular octane works just fine for most cars. However, when your car's manufacturer indicates premium gas is required, using a lower grade could damage your car, adversely affecting fuel efficiency.

But when premium gas is only recommended, not required, go for the cheaper, lower octane gas, says Reed.

Higher octane gas has only a marginal effect on performance, usually in the area of acceleration, according to Reed.

Car pool.

Skip Towne
03-24-2008, 05:25 PM
Your alternator will be turning anyway. It wouldn't require any more energy than is being used already.

Yep, it doesn't have a clutch like an air conditioner.

Donger
03-24-2008, 05:28 PM
Your alternator will be turning anyway. It wouldn't require any more energy than is being used already.

Not this again...

Once an additional load is placed upon the battery, the alternator will have to provide that current. Yes, it is always turning, but the load increases. Increased load = increased demand. Increased demand = more energy. Since gasoline is the only source of energy...

Donger
03-24-2008, 05:28 PM
Yep, it doesn't have a clutch like an air conditioner.

You really want to try this again?

Brock
03-24-2008, 05:30 PM
Not this again...

Once an additional load is placed upon the battery, the alternator will have to provide that current. Yes, it is always turning, but the load increases. Increased load = increased demand. Increased demand = more energy. Since gasoline is the only source of energy...

You should probably leave engineering discussions to engineers. You look dumb when you try to play along.

Donger
03-24-2008, 05:32 PM
You should probably leave engineering discussions to engineers. You look dumb when you try to play along.

Would you like to explain how energy is generated from nothing? I'd love to hear the explanation. Like I said, perhaps I'm missing something.

Skip Towne
03-24-2008, 05:33 PM
You really want to try this again?

I think you should.

Brock
03-24-2008, 05:35 PM
Would you like to explain how energy is generated from nothing? I'd love to hear the explanation. Like I said, perhaps I'm missing something.

The alternator is spinning all the time. Do you not understand this, or is it just the usual Donger Obtuse Act?

Donger
03-24-2008, 05:39 PM
The alternator is spinning all the time. Do you not understand this, or is it just the usual Donger Obtuse Act?

Yes, it is spinning all the time. But, when an electrical system increases demand, the load increases, and the alternator must generate more. It can only do that by taking power from another source. In this case, the only source available: the gasoline engine. Therefore, more gasoline is burned, reducing mileage.

Skip once tried to explain that running one's A/C unit doesn't decrease MPG. That's why I said, "not again." Unless it's running on pixie dust, it certainly does. It has to.

CrazyPhuD
03-24-2008, 05:39 PM
http://www.bicyclebuys.com/productimages/BHCAULFSAPART.jpg

Even cheaper way....

http://www.matcotools.com/ProductImages/mshi.jpg

Donger
03-24-2008, 05:40 PM
The alternator is spinning all the time. Do you not understand this, or is it just the usual Donger Obtuse Act?

Out of curiosity, what kind of engineer are you? ME? EE?

Skip Towne
03-24-2008, 05:43 PM
Yes, it is spinning all the time. But, when an electrical system increases demand, the load increases, and the alternator must generate more. It can only do that by taking power from another source. In this case, the only source available: the gasoline engine. Therefore, more gasoline is burned, reducing mileage.

Skip once tried to explain that running one's A/C unit doesn't decrease MPG. That's why I said, "not again." Unless it's running on pixie dust, it certainly does. It has to.

I never said an A/C won't decrease mileage, it will. But an alternator is producing its maximum already. It does not increase its output as more power is needed. That is what you fail to understand.

Calcountry
03-24-2008, 05:44 PM
Here is a sure fire way to save gas, DON'T DRIVE SO DA*N MUCH! Use the smallest car feasible for the trip, and by all means, leave the NASCAR driving to the pros on Sunday.

CrazyPhuD
03-24-2008, 05:49 PM
Out of curiosity, what kind of engineer are you? ME? EE?

Possibly sanitary?

alnorth
03-24-2008, 05:55 PM
Yes, it is spinning all the time. But, when an electrical system increases demand, the load increases, and the alternator must generate more. It can only do that by taking power from another source. In this case, the only source available: the gasoline engine. Therefore, more gasoline is burned, reducing mileage.

Bah, its obvious to me that these fine gentlemen have discovered an exception to the Law of Thermodynamics. You are going to look really silly when they give their Nobel Prize acceptance speech.

Brock
03-24-2008, 05:56 PM
Yes, it is spinning all the time. But, when an electrical system increases demand, the load increases, and the alternator must generate more. It can only do that by taking power from another source. In this case, the only source available: the gasoline engine. Therefore, more gasoline is burned, reducing mileage.

Skip once tried to explain that running one's A/C unit doesn't decrease MPG. That's why I said, "not again." Unless it's running on pixie dust, it certainly does. It has to.

If you have a 60 amp alternator, it's producing 60 amps ALL THE TIME whether you are using it or not. If the engine is spinning, the alternator is producing. The alternator has a static load on the engine. You don't have to take my word for it, just google it.

Brock
03-24-2008, 05:58 PM
It must be tough for some of you to admit you're basically a woman that wears men's clothes.

DaFace
03-24-2008, 06:02 PM
If you have a 60 amp alternator, it's producing 60 amps ALL THE TIME whether you are using it or not. If the engine is spinning, the alternator is producing. The alternator has a static load on the engine. You don't have to take my word for it, just google it.

I don't remotely claim to know how all this works, but that doesn't seem right to me. My car has a noticeable drop in power and gas mileage when my A/C is on, so increasing the "load" on the system HAS to come from somewhere.

Donger
03-24-2008, 06:03 PM
If you have a 60 amp alternator, it's producing 60 amps ALL THE TIME whether you are using it or not. If the engine is spinning, the alternator is producing. The alternator has a static load on the engine. You don't have to take my word for it, just google it.

An alternator's amp rating is it's maximum, not a constant.

What kind of engineer are you again?

Donger
03-24-2008, 06:04 PM
It must be tough for some of you to admit you're basically a woman that wears men's clothes.

Huh?

alnorth
03-24-2008, 06:05 PM
If you have a 60 amp alternator, it's producing 60 amps ALL THE TIME whether you are using it or not. If the engine is spinning, the alternator is producing. The alternator has a static load on the engine. You don't have to take my word for it, just google it.

We could expand on this by exploring the wonderful world of Ohm's Law (http://en.wikipedia.org/wiki/Ohm's_law).

I = V/R. If the resistance is increased, then to maintain the current at the same level, you need more voltage. As Donger might say, where does the extra voltage come from?

CrazyPhuD
03-24-2008, 06:10 PM
Or simply just google it....

http://en.wikipedia.org/wiki/Alternator

Automotive alternators invariably use a rotor winding, which allows control of the alternator generated voltage by varying the current in the rotor field winding.

Modern automotive alternators have a voltage regulator built into them. The voltage regulator operates by modulating the small field current in order to produce a constant voltage at the stator output. The field current is much smaller than the output current of the alternator; for example, a 70-amp alternator may need only 2 amps of field current.

Relevant bits...

It's the voltage regulator that adjusts the field output. The total output is dependent upon load, RPM and field current. The more power you need the more drag that occurs on the engine.

DaFace
03-24-2008, 06:13 PM
Or simply just google it....

http://en.wikipedia.org/wiki/Alternator





Relevant bits...

It's the voltage regulator that adjusts the field output. The total output is dependent upon load, RPM and field current. The more power you need the more drag that occurs on the engine.

Confirmed by the web sites I've found. If the alternator were "running at maximum" all the time, it wouldn't make a difference if you added something else to the system unless you were using more than the alternator was producing, at which point it would drain your battery, then eventually die. Since it doesn't, the more energy you use, the harder your car has to work at turning the alternator due to increased resistance. The harder your car works, the more gas used.

Donger
03-24-2008, 06:17 PM
You guys look really dumb, you know that?

I'm stunned every time this question comes up. Especially when "engineers" bring it up.

CrazyPhuD
03-24-2008, 06:25 PM
You guys look really dumb, you know that?

I'm stunned every time this question comes up. Especially when "engineers" bring it up.

http://www.billcigliano.com/images/port_edit/PT_Barnum_web2b.jpg

Chiefmanwillcatch
03-24-2008, 06:36 PM
Getting you car to work on restaurant leftover oils would help.

Luke
03-24-2008, 06:50 PM
There was a time in the not so distant past when the Federal Government in its infinite wisdom decided that the speed limit should be 55 mph and so regulated it in most states. That is why "older" vehicles have the red marking at 55 on speedometeres. Not being Sammy H, I have found that 55 does optimize my mpg, it just seems to take forever to get anywhere, in reality it only adds 5 to 10 minutes per hour versus 5 to 7 mpg. A toss up to most folks. At my advanced age I have no problem driving in the right hand lane.:doh!:

Bugeater
03-24-2008, 06:50 PM
I don't remotely claim to know how all this works, but that doesn't seem right to me. My car has a noticeable drop in power and gas mileage when my A/C is on, so increasing the "load" on the system HAS to come from somewhere.

I'm no engineer, but I can tell you that's different because the A/C compressor cycles on and off, when it's not running the only resistance is the bearings.

As far as the alternator goes, I always was under the assumption that it put out a certain amount of power constantly and you used whatever you needed. Regardless of that, there is a void between the two windings inside of it, there's nothing to create friction which would cause an increase in drag on the engine. The only resistance should be the bearings, and that shouldn't vary. OTOH, if the additional amps needed under load did somehow create some additional electrical resistance, I would think it would be minimal vs an ICE.

Skip Towne
03-24-2008, 07:16 PM
I'm no engineer, but I can tell you that's different because the A/C compressor cycles on and off, when it's not running the only resistance is the bearings.

As far as the alternator goes, I always was under the assumption that it put out a certain amount of power constantly and you used whatever you needed. Regardless of that, there is a void between the two windings inside of it, there's nothing to create friction which would cause an increase in drag on the engine. The only resistance should be the bearings, and that shouldn't vary. OTOH, if the additional amps needed under load did somehow create some additional electrical resistance, I would think it would be minimal vs an ICE.

Agreed.

Buehler445
03-24-2008, 07:24 PM
Not this again...

Once an additional load is placed upon the battery, the alternator will have to provide that current. Yes, it is always turning, but the load increases. Increased load = increased demand. Increased demand = more energy. Since gasoline is the only source of energy...

I doubt the demand from a little electrode would translate into any appreciable drop in mileage.

The spark plugs and stereo account for most of it IIRC.

That being said, the Hydrogen thing problably doesn't work.

Donger
03-24-2008, 07:27 PM
I'm no engineer, but I can tell you that's different because the A/C compressor cycles on and off, when it's not running the only resistance is the bearings.

As far as the alternator goes, I always was under the assumption that it put out a certain amount of power constantly and you used whatever you needed. Regardless of that, there is a void between the two windings inside of it, there's nothing to create friction which would cause an increase in drag on the engine. The only resistance should be the bearings, and that shouldn't vary. OTOH, if the additional amps needed under load did somehow create some additional electrical resistance, I would think it would be minimal vs an ICE.

A question for you: you are sitting there at idle and you think, "Wow. It's hot." And, you turn on your A/C. Does the RPM of your engine increase when you turn on the A/C?

Bob Dole
03-24-2008, 07:30 PM
Here is a sure fire way to save gas, DON'T DRIVE SO DA*N MUCH! Use the smallest car feasible for the trip, and by all means, leave the NASCAR driving to the pros on Sunday.

Killjoy.

How the **** else are we supposed to show everyone else how affluent we are if we don't drive the largest vehicle we can't really afford?

CrazyPhuD
03-24-2008, 07:35 PM
I'm no engineer, but I can tell you that's different because the A/C compressor cycles on and off, when it's not running the only resistance is the bearings.

As far as the alternator goes, I always was under the assumption that it put out a certain amount of power constantly and you used whatever you needed. Regardless of that, there is a void between the two windings inside of it, there's nothing to create friction which would cause an increase in drag on the engine. The only resistance should be the bearings, and that shouldn't vary. OTOH, if the additional amps needed under load did somehow create some additional electrical resistance, I would think it would be minimal vs an ICE.

Every played with magnets as a kid? The resistance here has nothing to do with air or friction. The alternator runs via magnetic fields. Ever tried to push two north ends of a magnet together? It's really difficult even with weak magnets. You might not be able to see the forces involved but they are there.

Power is generated in an alternator by the intensity of the magnetic field and the number of RPMS of the alternator. If you need more power the voltage regulator increases the magnetic field(up to a limit). The higher the magnetic field the more difficult it is to turn the alternator.

One way to think of it is the two north ends of two magnets. The closer you get them together, the stronger the magnetic field between them and the more difficult it is to get them closer. You can push the two north ends closer together but it will take more energy.

The alternator does something related, when more power is needed, the magnetic field's intensity is increased. This increase in magnetic field increases the amount of power generated per rotation. However the alternator is more difficult to turn. As a result more of the engine's HP is used to drive the alternator.

You can't see the forces involved but they are there. The engine is the only source of power, it generates exactly what you need to overcome rolling resistence minus thermal losses. If you turn on the radio or the A/C, it takes power and that comes out of the engine. As a result the engine opens the throttle plate to allow more air into the engine. With more air comes more fuel, which brings more power. This is why the fuel economy drops for any electrical load in the system. Most electronics don't have a major impact on fuel economy because the power demands are low. The A/C is generally one exception.(that said you get better gas milage with the A/C on generally than with the windows down, because the extra drag generated by having the windows down requires more power to overcome than the A/C uses.)

Bugeater
03-24-2008, 07:36 PM
A question for you: you are sitting there at idle and you think, "Wow. It's hot." And, you turn on your A/C. Does the RPM of your engine increase when you turn on the A/C?

As I already pointed out, comparing an A/C compressor to an alternator is apples to oranges, they operate in a completely different manner. Explain to me how turning on every electrical device in my car creates additional drag on my engine, I honestly don't understand how it could possibly make a significant impact.

Buehler445
03-24-2008, 07:37 PM
Here is what my dad says about alternators. He is no engineer, but he is a farmer :)
It senses the state of the battery and the load on the battery (lights etc) and the lower the battery the more the charge. when it is charged up and no other draw is sensed it governs the electeral output down to nothing. That is all done with a transistor voltage regulator. the regulator is like a valve that controls the amount of electercity into the alternator windings. The more electicity in the stronger the magnetic field and the more the charge.

Donger
03-24-2008, 07:40 PM
As I already pointed out, comparing an A/C compressor to an alternator is apples to oranges, they operate in a completely different manner. Explain to me how turning on every electrical device in my car creates additional drag on my engine, I honestly don't understand how it could possibly make a significant impact.

Since your A/C works on the power provided by your alternator, you should. What do you think it is powered off of?

The ONLY source of energy in your car is your gasoline engine. Therefore, every thing (A/C, windows, stereo, etc.) that you turn on makes a demand load on that power source.

Bugeater
03-24-2008, 07:41 PM
Every played with magnets as a kid? The resistance here has nothing to do with air or friction. The alternator runs via magnetic fields. Ever tried to push two north ends of a magnet together? It's really difficult even with weak magnets. You might not be able to see the forces involved but they are there.

Power is generated in an alternator by the intensity of the magnetic field and the number of RPMS of the alternator. If you need more power the voltage regulator increases the magnetic field(up to a limit). The higher the magnetic field the more difficult it is to turn the alternator.

One way to think of it is the two north ends of two magnets. The closer you get them together, the stronger the magnetic field between them and the more difficult it is to get them closer. You can push the two north ends closer together but it will take more energy.

The alternator does something related, when more power is needed, the magnetic field's intensity is increased. This increase in magnetic field increases the amount of power generated per rotation. However the alternator is more difficult to turn. As a result more of the engine's HP is used to drive the alternator.

You can't see the forces involved but they are there. The engine is the only source of power, it generates exactly what you need to overcome rolling resistence minus thermal losses. If you turn on the radio or the A/C, it takes power and that comes out of the engine. As a result the engine opens the throttle plate to allow more air into the engine. With more air comes more fuel, which brings more power. This is why the fuel economy drops for any electrical load in the system. Most electronics don't have a major impact on fuel economy because the power demands are low. The A/C is generally one exception.(that said you get better gas milage with the A/C on generally than with the windows down, because the extra drag generated by having the windows down requires more power to overcome than the A/C uses.)

First of all, the reason the A/C compressor takes so much power is because it's PHYSICALLY compressing freon, which takes a hell of a lot more power than spinning an alternator. Your A/C IS NOT powered by your alternator at all, other than the blower motor. I'm not going to dispute the alternator creates a bit of magnetic resistance, but have you ever tried to stop an ICE from turning with your hand?

Donger
03-24-2008, 07:42 PM
Your A/C IS NOT powered by your alternator at all, other than the blower motor.

What is powering it, then?

Bugeater
03-24-2008, 07:43 PM
Since your A/C works on the power provided by your alternator, you should.
No, it doesn't. Only the blower motor does.

What do you think it is powered off of?
You have no idea how an automotive air conditioner works, do you?

Donger
03-24-2008, 07:45 PM
No, it doesn't. Only the blower motor does.


You have no idea how an automotive air conditioner works, do you?

If you can tell me what other power source is in your car, I'd be happy to hear it.

Bugeater
03-24-2008, 07:46 PM
What is powering it, then?

The engine is powering the compressor directly, not via the alternator. When you turn on your car A/C, the drag you sense is from the compressor, not the alternator.

Donger
03-24-2008, 07:47 PM
The engine is powering the compressor directly, not via the alternator. When you turn on your car A/C, the drag you sense is from the compressor, not the alternator.

How is the engine powering the compressor directly?

DaFace
03-24-2008, 07:48 PM
First of all, the reason the A/C compressor takes so much power is because it's PHYSICALLY compressing freon, which takes a hell of a lot more power than spinning an alternator. Your A/C IS NOT powered by your alternator at all, other than the blower motor. I'm not going to dispute the alternator creates a bit of magnetic resistance, but have you ever tried to stop an ICE from turning with your hand?

Intersting. I never knew that.

After another quick Google search, it seems that a car's A/C is belt-driven and is not electrical like a home air conditioning system. THAT'S why you notice such a difference when it's on.

That doesn't change the fact that the alternator has to work harder when electrical devices are running. However, I have to agree with Buehler - a little hydrogen gizmo probably isn't going to make a huge difference (and the hydrogen gizmo probably doesn't do much of anything to help either).

Buehler445
03-24-2008, 07:48 PM
What is powering it, then?

DUDE. The cold comes from freon which is compressed by the compressor which is turned by the belt which is driven by the motor. The drain in power comes from the compressor turning NOT the alternator.

Donger
03-24-2008, 07:49 PM
DUDE. The cold comes from freon which is compressed by the compressor which is turned by the belt which is driven by the motor. The drain in power comes from the compressor turning NOT the alternator.

What powers the compressor?

Bugeater
03-24-2008, 07:49 PM
How is the engine powering the compressor directly?
Do you seriously not know how this works? If you don't, you shouldn't be here arguing about it.

Buehler445
03-24-2008, 07:50 PM
DUDE. The cold comes from freon which is compressed by the compressor which is turned by the belt which is driven by the motor. The drain in power comes from the compressor turning NOT the alternator.
http://www.aa1car.com/library/2003/elements/AC-Update.gif

The Compressor is what does the cooling. The only electricity (that comes from the alternator) is the blower.

DaFace
03-24-2008, 07:51 PM
What powers the compressor?

I think you're on the wrong argument at this point. In the end, the compressor is fuel-powered like everything else in the car. No one's arguing that.

The original question was whether an alternator has to work harder when an extra electrical device is being used. The A/C apparently has nothing to do with that.

Skip Towne
03-24-2008, 07:51 PM
As I already pointed out, comparing an A/C compressor to an alternator is apples to oranges, they operate in a completely different manner. Explain to me how turning on every electrical device in my car creates additional drag on my engine, I honestly don't understand how it could possibly make a significant impact.

When your A/C is off, the compressor doesn't run. Only the flywheel (I guess you'd call it) turns. When you turn the A/C on a clutch engages the compressor and creates signifcant drag on the engine. But an alternator runs full speed all the time regardless of the energy being used.

Donger
03-24-2008, 07:51 PM
Do you seriously not know how this works? If you don't, you shouldn't be here arguing about it.

My entire premise is that EVERYTHING that is in your car is driven by the energy that is created by the combustion of gasoline (or diesel). That's all. Therefore, everything else that you have running will decrease fuel efficiency.

Buehler445
03-24-2008, 07:52 PM
What powers the compressor?

DUDE. The cold comes from freon which is compressed by the compressor which is turned by the belt which is driven by the motor. The drain in power comes from the compressor turning NOT the alternator.

I am absolutely not arguing that the a/c takes power (gas). I'm just saying it is completely independent of the alternator.

Bugeater
03-24-2008, 07:55 PM
Intersting. I never knew that.

After another quick Google search, it seems that a car's A/C is belt-driven and is not electrical like a home air conditioning system. THAT'S why you notice such a difference when it's on.
Exactly, you're feeling the A/C compressor cycling on and off. It's not the alternator doing that.

t the alternator has to work harder when electrical devices are running. However, I have to agree with Buehler - a little hydrogen gizmo probably isn't going to make a huge difference (and the hydrogen gizmo probably doesn't do much of anything to help either).
I'm not disputing the alternator may have to work a bit harder, but its impact on fuel mileage has to be extremely minimal, if not immeasurable. I think Donger knows that and just doesn't want to admit it because then he'd have to say that Skip is right.

tiptap
03-24-2008, 08:00 PM
You know Donger, while all the energy comes from the gasoline for the engine, the efficiency in use of that energy may see merit in how the system is tuned and utilized. Efficient transfer of energy is especially seen in chemical half cell systems. That would include the production of Hydrogen. I would prefer some inertia system that reclaims energy when stopping though as a more realistic increase in efficiency especially with larger vehicles. So what is it that both sides are talking about. One is absolute energy and one is efficiency. One is 1st law related and the other is 3rd law related. One is about fuel set the other is all about engines.

CrazyPhuD
03-24-2008, 08:08 PM
First of all, the reason the A/C compressor takes so much power is because it's PHYSICALLY compressing freon, which takes a hell of a lot more power than spinning an alternator. Your A/C IS NOT powered by your alternator at all, other than the blower motor. I'm not going to dispute the alternator creates a bit of magnetic resistance, but have you ever tried to stop an ICE from turning with your hand?

Yes, I was paying too much attention to DOnger's posts with the electric A/C ;) The A/C is belt fed.

So you want to know the load that can be generated by the alternator, here's simple math. Assume a 100 AMP alternator. At max output it's producing 1440 Watts of power. Each HP is around 700 Watts worth of power so you're alternator is consuming 2HP if it were 100% efficient(but it's not, it's actually around 50% efficient). As a result the alternator is consuming 4HP to produce 2 HP worth of energy.

Doesn't sound like much but it's still enough to drop fuel economy by 2% on a 200HP engine if you're running max power(fortunately we don't often).

Back to the original argument(i.e. water electrolysis to generate hydrogen). Just due to conservation of energy you would need to spend one watt of energy to break the water into hydrogen and oxygen. Due to conservation of energy if you had perfect combustion efficiency(which you never do it's around 25%) you would get 1W of power for every 1W you put into the engine. However because the alternator is only 50% efficient, you would pull out 2W of power for every 1W of power you added. In the ideal case if you wanted to produce 50HP of extra power through combusting hydrogen you would need an alternator that would consume 100HP of power to output 50HP.

The net effect is that you add 50 HP and subtract 100HP. To get any real power out of any of these approaches you would have to have a massive alternator to break enough water into H2. The thermal inefficiencies say you lose power(actually much worse than I described).

Donger
03-24-2008, 08:17 PM
Exactly, you're feeling the A/C compressor cycling on and off. It's not the alternator doing that.


I'm not disputing the alternator may have to work a bit harder, but its impact on fuel mileage has to be extremely minimal, if not immeasurable. I think Donger knows that and just doesn't want to admit it because then he'd have to say that Skip is right.

See 106. The ICE powers the belt and the ICE powers the alternator. Therefore, fuel efficiency drops whenever a new load is introduced.

CrazyPhuD
03-24-2008, 08:22 PM
I think part of the problem here is that we're all arguing different somewhat different points here and are confused that the other party doesn't get it.

Bugeater
03-24-2008, 08:24 PM
Yes, I was paying too much attention to DOnger's posts with the electric A/C ;) The A/C is belt fed.

So you want to know the load that can be generated by the alternator, here's simple math. Assume a 100 AMP alternator. At max output it's producing 1440 Watts of power. Each HP is around 700 Watts worth of power so you're alternator is consuming 2HP if it were 100% efficient(but it's not, it's actually around 50% efficient). As a result the alternator is consuming 4HP to produce 2 HP worth of energy.

Doesn't sound like much but it's still enough to drop fuel economy by 2% on a 200HP engine if you're running max power(fortunately we don't often).

Well that's more than I would've guessed. I figured we'd be talking about a number with a decimal point followed by a zero or two.

Bugeater
03-24-2008, 08:28 PM
I think part of the problem here is that we're all arguing different somewhat different points here and are confused that the other party doesn't get it.
That's because not everyone understands how a car air conditioner works.
See 106. The ICE powers the belt and the ICE powers the alternator. Therefore, fuel efficiency drops whenever a new load is introduced.
I've never disputed that. I just wanted to know what impact the alternator by itself had, as that was where the original disagreement originated. You just made it more difficult than it had to be by bringing up the A/C.

CrazyPhuD
03-24-2008, 08:29 PM
Well that's more than I would've guessed. I figured we'd be talking about a number with a decimal point followed by a zero or two.

Yea I'm sure it's somewhat on the high side but I wouldn't be surprised if it was close to 1% power consumed. The big question is what percentage of the rated power is your alternator running at.

You actually might be surprised how power hungry the engine is. I noticed this when I had a battery cable fall off while I was driving. When I was idling, my radio and engine was fine. But if I accelerated from a stop my radio stopped because the alternator didn't have enough juice to run both the engine at high load and the radio at the same time. Fortunately I guess what was going on(especially when I stopped and lost all electrical power), but it was a bit freaky to realize that there wasn't as much head room on the alternator as I thought. Cars rely upon the battery to even out power demand.

Bugeater
03-24-2008, 08:35 PM
Yea I'm sure it's somewhat on the high side but I wouldn't be surprised if it was close to 1% power consumed. The big question is what percentage of the rated power is your alternator running at.

You actually might be surprised how power hungry the engine is. I noticed this when I had a battery cable fall off while I was driving. When I was idling, my radio and engine was fine. But if I accelerated from a stop my radio stopped because the alternator didn't have enough juice to run both the engine at high load and the radio at the same time. Fortunately I guess what was going on(especially when I stopped and lost all electrical power), but it was a bit freaky to realize that there wasn't as much head room on the alternator as I thought. Cars rely upon the battery to even out power demand.
Yep, that's another common misconception, the alternator's job isn't to power the electrical system, the battery does that. The alternator just charges the battery as its power is depleted.

Skip Towne
03-24-2008, 08:48 PM
Actually, your alternator puts out more voltage than your battery. Not sure about the amperage. A simple test if you want to know if your alternator is out is to use a voltmeter to check the DC voltage (at the battery) with the vehicle off. It should check between 12 and 13 volts. Then start the car and check it again. It should go up to about 14.5 volts. If it checks the same, it's the alternator.

Donger
03-24-2008, 08:49 PM
That's because not everyone understands how a car air conditioner works.

I've never disputed that. I just wanted to know what impact the alternator by itself had, as that was where the original disagreement originated. You just made it more difficult than it had to be by bringing up the A/C.

I didn't bring up the A/C.

Donger
03-24-2008, 08:52 PM
Yep, that's another common misconception, the alternator's job isn't to power the electrical system, the battery does that. The alternator just charges the battery as its power is depleted.

See, I disagree. The battery is just a power reserve. The alternator does the work. The battery just distributes the energy.

Well, to be fully accurate, the gasoline engine does the work.

Skip Towne
03-24-2008, 09:07 PM
I didn't bring up the A/C.

Actually you did. See post 65.

Donger
03-24-2008, 09:12 PM
Actually you did. See post 65.

Did you forget #58?

Buehler445
03-24-2008, 09:12 PM
See, I disagree. The battery is just a power reserve. The alternator does the work. The battery just distributes the energy.

Well, to be fully accurate, the gasoline engine does the work.

Two different uses of the word "power"

Donger
03-24-2008, 09:16 PM
Two different uses of the word "power"

Not at all. Power is defined as "a source or means of supplying energy." The gasoline burning is the source of supplying ALL energy in vehicle, period.

Buehler445
03-24-2008, 09:20 PM
Not at all. Power is defined as "a source or means of supplying energy." The gasoline burning is the source of supplying ALL energy in vehicle, period.

I think GoBo knows that batteries don't make energy. I think EVERYONE knows batteries don't make energy, but when the alternator turns, it charges the battery, which stores it for usage in the vehicle. So technically the battery powers the car's electronic systems (hence why you can use your accessories when the engine is off, or your sparkplugs will spark when your alternator is broken), but the battery gets its power from the alternator (engine).

I think everyone understands that the only source of power for the car is the engine. Accordingly, everything that is added affects the efficiency of the engine.

Skip Towne
03-24-2008, 09:36 PM
See 106. The ICE powers the belt and the ICE powers the alternator. Therefore, fuel efficiency drops whenever a new load is introduced.

Totally incorrect. The alternator supplies more power than the vehicle can use all the time. If it isn't needed it isn't used. Just like an unused electrical outlet in your home. But this is typical Donger. He just comes here to argue. He knows absolutely nothing about football and cars too apparently.

Donger
03-24-2008, 09:40 PM
Totally incorrect. The alternator supplies more power than the vehicle can use all the time. If it isn't needed it isn't used. Just like an unused electrical outlet in your home. But this is typical Donger. He just comes here to argue. He knows absolutely nothing about football and cars too apparently.

No, it doesn't. You've been given many examples of the load factors involved, yet you choose to ignore the physics.

I fully admit that I don't know much about football, so I fail to understand your reasoning behind bringing that up.

If I cared enough, I would go and search your for your post that A/C doesn't increase MPG, but honestly, that'd be like smacking a dead horse.

Bugeater
03-24-2008, 09:49 PM
No, it doesn't. You've been given many examples of the load factors involved, yet you choose to ignore the physics.

I fully admit that I don't know much about football, so I fail to understand your reasoning behind bringing that up.

If I cared enough, I would go and search your for your post that A/C doesn't increase MPG, but honestly, that'd be like smacking a dead horse.

OK, tell me you mistyped something there....

Donger
03-24-2008, 10:10 PM
OK, tell me you mistyped something there....

Nope. IIRC, Skip once claimed that running one's A/C has no effect on fuel efficiency.

Edit: Yeah, that was confusing the way I wrote it. I should have written: "A/C doesn't decrease fuel efficiency."

Bugeater
03-24-2008, 10:16 PM
Nope. IIRC, Skip once claimed that running one's A/C has no effect on fuel efficiency.

Edit: Yeah, that was confusing the way I wrote it. I should have written: "A/C doesn't decrease fuel efficiency."

Thank you, I was worried I was going to have to spend another hour arguing about that one.

Guru
03-24-2008, 10:22 PM
I'm just saying. British Petroleum is one of the largest oil companies in the world. They owned Amoco, which used to be popular around here. Then they got rid of the Amoco brand and went straight to BP. In the south, BP is EVERYWHERE and you'll rarely find a Philips 66. It's weird.

EDIT: And it's very possible that you are getting worse gas mileage with them, depending on their ethanol content. Many cars get much worse gas mileage with higher ethanol in the gas.

Definitely. I have severely changed the way I drive to squeeze every last mile out of my tank. Feel like I am losing the battle though.

Bugeater
03-24-2008, 10:49 PM
Definitely. I have severely changed the way I drive to squeeze every last mile out of my tank. Feel like I am losing the battle though.
Well according to Donger, your engine is the main culprit, so maybe you should just remove the damn thing. :shrug:

Bob Dole
03-24-2008, 11:09 PM
Totally incorrect. The alternator supplies more power than the vehicle can use all the time. If it isn't needed it isn't used. Just like an unused electrical outlet in your home. But this is typical Donger. He just comes here to argue. He knows absolutely nothing about football and cars too apparently.

So there's no friction at all caused by that belt looped around the pulley on the front of the alternator?

Guru
03-24-2008, 11:43 PM
Well according to Donger, your engine is the main culprit, so maybe you should just remove the damn thing. :shrug:

I haven't read every single post here but I don't think that is his ultimate point. Seems to me that he is just going to an extreme to point out that nothing will run without oil no matter what new technology is out there.

I am doing everything I can to save but am finding that it may not be worth all the effort I am putting into it just to save a few bucks per fillup.

Bugeater
03-25-2008, 12:43 AM
I haven't read every single post here but I don't think that is his ultimate point. Seems to me that he is just going to an extreme to point out that nothing will run without oil no matter what new technology is out there.

I am doing everything I can to save but am finding that it may not be worth all the effort I am putting into it just to save a few bucks per fillup.
That post was a feeble attempt at humor.

Guru
03-25-2008, 12:46 AM
That post was a feeble attempt at humor.

As was yours. heh

Bugeater
03-25-2008, 12:53 AM
As was yours. heh

I was referring to my post. You're not on the ball at all tonight, I hope you're not being distracted by your job.

Guru
03-25-2008, 12:56 AM
I was referring to my post. You're not on the ball at all tonight, I hope you're not being distracted by your job.

Quite astute there for a Gawd Damned Nebraskan.