Automatic Horsepower Loss

[SMG]

Hey Guys,

I read on here somewhere that drivetrain power loss in the automatic is something like 30%, while the manual is only like 15%, meaning the manual puts more horsepower to the ground.

I can't find this info to back me up, am I going crazy? :crazy:

Any help (and links) appreciated!

SMG

[hannaco]

No, you are not going crazy. Try www.vw.de (http://www.vw.de) Or, www.dub-tech.com (http://www.dub-tech.com) and ask Walt.

[Toad]

It's mainly becuase of one big heavy swishy thing that old-school autos have, and it's called a torque converter. The Torque converter is a big chamber filled with fluid that basially allows the car to stay in gear and be completely stopped without stalling the engine. And with the miracle of old-school engineering, the engine spins one part of it, and the fluid makes the other part spin - sending the power thru the tranny and out to the tires.

Newer autos (DSG, CVT) dont have this horrible thing, and claim to be as efficient as manuals.

i think i read that on howstuffworks.com d=

[oneighturbo]

when i dyno'd i was told 20-25%

[jim]

It depends on the transmission. Some will but some won't i.e. Powerglide vs Hydramatic. If you look at the EPA gas mileage estimate you'll get an idea of how much power difference there is. Gearing is the most important issue.

[BoostedOne]

Yeah, and from what I understand 30% out of a modern FWD transaxle is kinda rediculous. 30% numbers are usually for big, oldschool trannies like a Ford C6 or a TH400.