Originally Posted by MIAdragon
I think DJ is right here. The difference in parasitic loss is what 18% for an auto and 15% for manual, that measly 3% is easily made up by a computer controlled trans. This argument was true 25 years ago when the auto's were power glides and TH400's. Today's autos are VERY efficient, If manuals truly were more efficient you would see them in cars like the Prius that ONLY come in an auto.
I donít necessarily disagree with that. If an engine is making enough power the difference in parasitic loss is negligible, and modern transmissions have become much more efficient than they used to be.
With the Prius youíve got a lot of things going on other than just delivering power to the wheels. Like when you first hit the brakes in a Prius youíre not actually putting brake pad to disk, itís actually connecting the electric motor in reverse as it spins it is charging the batteries. This is how they get their fantastic mileage in stop and go traffic. Thatís also something I donít think would be easy to accomplish with a manual transmission.