I had no idea it would be benificial to leave the tranny in drive for that, I thought that it was bad for the tranny to leave it in drive when over 45mph.

This "hunting" you talk about.. is it when the tranny is slow to shift? Mine isn't slow, but when WOT in 1st, shifting at redline to 2nd [manually], it is very harsh. Not to mention before I put in some transtune, it would take like 5 seconds to down shift, manually.


-justin

hunting refers to when the car doesn't know which gear to be in, so you get a constant upshift/downshift/upshift, and repeat.

The 2000+ models with the 4T65E HD are different too.
If you leave it in 3rd or drive, it will shift at wide open throttle at a lower rpm than if you leave it in Drive which is really Overdrive.
Best to just leave it in D.
1,2,3,D,N,R

in my car manual for my 91 le it says for best feul economy it is best to keep it in od all the time

You must mean the lock up feature of the torque converter. There is a clutch pack in the torque converter that effective locks it up so it acts like a direct connection between the engine and the rest of the drivetrain. It is electronically controlled.

A non lock up type of torque converter, like in my TurboHydramatic 350 that my Firebird has, will always slip a little, about 3-5% slippage at higher speeds.

When a lock up type locks, the rpm will drop noticeably, like going into a higher gear, improving fuel efficiency.