|
With auto tranny, it is more effiecient to leave the overdrive off until higher speed ( let said 40 mph ) Overdrive off means the car is running at 1st to 3rd gear, turn on overdrive then it will run at 1st to 4th gear.
Power is more direct from the engine to the tranny with overdrive off, and it also provide engine braking when you slow down.
When you start from 0, the quickest way to launch is ( I believe ) have the overdrive off, left foot step on the brake, and the same time put you right foot on the gas, rev it to above 3500rpm ( don't rev too high, don't rev for more than 10 sec or you will burn your torque convertor ), then let go the brake. This actually the way they drag race with auto tranny.
At freeway speed, you can turn off the overdrive when you want to acelerate, but the more direct way is push the gas pedal all the way to the floor, the tranny will automaticly "kick down" to 3rd for full aceleration.
|