BullWinkle said:Is it true that there is less parasitic loss in a 6 speed as compared to an auto?
The automatic tranmission uses bands and clutches and fluid to transmit force. It also uses a torque converter, mounted behind the flywheel. It is in two parts. The front half (engine-side) has vanes which swirl the fluid inside the torque converter. This swirling fluid strikes the vanes on the transmission-side half of the torque converter. This cause force to be transitted to the planetary gears. There is a considerable amount of parasitic drag produced by this process which robs some of the available force used to drive the output shaft which is connected eventually to the rear wheels. That is why early hot rodders refered to an automatic as a slush box.
The 6-speed manual has some parasitic loss due to the friction of meshed gears. The finer the gear cuts, the less loss. Rougher cuts produce more frictional loss. But overall, the manual transmits more force to the differential giving better acceleration and better fuel economy.
Generally speaking, a stock auto transmission will transmit less force to the rear wheels than will a manual transmision, because an automatic loses more internally.
But more importantly, God intended that sports cars have a manual transmission. As a matter of fact, God drives a Z06.