Re: Drive or Overdrive?
I, for the most part, tow with OD on if I'm on the highway. My truck (98 Dodge Ram 1500), rarely will shift out of OD at highway speeds.
I have the Mag-Hytec Aluminum high capacity trans pan, and a tranny temp gauge installed. (Plus the factory tow pkg.)
I towed in 88 Deg humid heat last weekend, doing 75mph on the freeway from Mpls to Des Moines, and my tranny fluid never got over 165 degrees.
The extra 2 qts it holds, plus the higher heat transfer rate of the aluminum pan really has dropped 20-40 degrees off my fluid temps. Its been well worth the cost.
My drive though is very flat, so it rarely shifted out of OD. We were fully loaded from our week up north, so there was quite a bit of weight back there.
If I had more weight though, I would be listening for lots of shifting, slowing down, and taking it out of OD most likely.