does anyone know why manual cars get better milege than auto trannys?

 

An automatic tranny has more moving parts than manual and are actuated be efforts of the motor as opposed to efforts of the driver.

 

One of the biggest contributors to the loss of efficiency is the torque converter, which replaces the clutch in a manual tranny.

 

Hmmm....i'm also pretty sure the reason why is that -- until recently, automatics have mostly been 4 speed wheras the standard car is 5 speed. That extra gear lowers the drive ratio more and you save gas.

Am i right?

 

Yes.

 

Notice that Automatics have cooling lines running from the trans to the radiator and that Manuals don't. There's not as much heat (power) loss through the manual as there is in the auto. Torque converter slippage, pumps, etc...

 

All the above plus the additional weight an automatic has give it worse fuel economy.

 

Yep, I second all the replies. My job has been done here before me even doing anything
Ed

 

what exactly is a torque converter and how does it act as a clutch?

 

In simple terms - the converter transmits torque from one shaft to another(engine to the transmission), producing a different torque in the other shaft.

It performs a simular function as the clutch in a standard transmission, w/o it you would constanlty stall/peel out depending on conditions, etc. They can be tuned(custom built) for specific street/race applications depending on your needs - manufatures tend to tune them for longetivity of drivetrain components with no stall design.

Thats about all I know about them - Hope this helps.

 

http://www.howstuffworks.com/torque-converter.htm