Performance from the automatic transmission

[accordaffair]

I was reading up on how our automatic transmissions work, and it says that in D4, lockup is used on 2nd, 3rd, and 4th gears. In D3, lockup is present only in 3rd gear (4th is not present obviously).

Please correct me if I'm wrong, but "lockup" is the enemy of power in auto's, right? So, if you want the maximum amount of power out of the transmission, from a stop you should leave it in D3 until the end of 3rd at which you should then switch to D4, thereby avoiding lockup in 2nd gear. Gearing manually from 1-2-D3-D4 would not be anymore beneficial (in terms of avoiding lockup).

I read that lockup is used to increase gas mileage, and therefore I assume it decreases power.

Accelerating from a stop while leaving the selector in D4 would use the lockup in 2nd, 3rd, and 4th gear, which would result in slower accelerating.

Is any of this correct, or am I an absolute idiot? Or both? LMK and TIA.

[pretty_ricky302]

i think ur right when i drive i live it in d3 til i hit about 70 the go to d4, but i think drivin like this burns alot more gas

[Frazzums]

Hmm....i never really drove in d4 and then shifted into d4 while trying to race or what not...

But ill try this later and tell you guys if my butt dyno feels a change.

[owequitit]

I do believe lock up would be the equivalent of having the clutch fully engaged, i.e. no slip in the drivetrain.

Better for gas mileage, for sure, but probably for power too.

Installing higher stall converters, may have to with launching, or the amount of torque generated. I think with the old ones, they locked based on torque, and higher stall converters required more torque to lock.

If the stall speed was too low, and power too high, you would get premature lockup.

I will have to do some reading. I will post back if someone else doesn't first.