Most of my driving is in town 45 mph and less...I always put the car in overdrive right from when i start it up and drive away..is it better for the car for me to use Drive in town or is overdrive fine?

Leaving it in OD is fine BELOW that speed, when the TCC isn't trying to lockup. You don't want it to be locking and unlocking constantly. If you're driving around 45 alot, but not above, I'd leave it in D.

wilwren, I have been using that gear (D) lately since most of the posted speed limits where I live average anywhere from 30 to 45 mph. Seems to work for me.

Don, You are correct. Right around 47-48mph is when mine will kick in to OD. We have one major road where the speed limit is 45mph but alot of traffic lights along the way. I just started using (D) within the last few days just to keep the TCC from doing it'* thing at that speed range.

Hmm thanks im gunna start using D from now on!

Yeah, Let the TCC have a little R&R.

It'* torque convertor lockup rather than an overdrive gear, but 47 is where it occurs. If you set your cruise at 46 mph on a level road, then tap the Resume/Accel slide switch once to step up to 47, you should see the lockup engage, accurate to 1 mph; it'* very precise.

For disengaging based on speed (i.e. as long as you don't touch the brake pedal) it'* kind of a sliding scale; I don't think it disengages the instant road speed dips below 47 mph, but the car does keep track of _exactly_ how fast it'* going when determining shift points and lockup points.

I will have to try this procedure within the next few days. Haven't even used the cruise control yet. Thanks.

I've was told once by a supposed tranny specialist that there are way more other bad things going on in a stock Pontiac tranny in low speed operation, and shifting into OD and back once in a while is the least of its worries...

I took his word at it, and never use anything but OD. My last non-bonne had no problems till its rusty death at 210,000 city kms....so I don't expect much problem from the Bonnes either.

.. I feel that it would be better to be in drive up to 45 - 46 mph instead of having the TCC apply and release a million times... Just my opinion... [/quote]
Don, Your opinion is well taken. Have been using (D) for about a week now around town. I definately notice a difference.