Originally Posted by ChrisSlicks

I try to keep it close to 65, but will do 70 on the flats. I had a trailer tire blow out at 75 mph from what appeared to be tread separation (overheated) and it sounded like someone had dropped a bomb under my truck. Took a while to unweave the separated tread that was wrapped around the axle.

I get the biggest improvement by not trying to steam up the hills too hard. Build momentum before the hill, let some of the speed fall away slowly as you climb and use as much throttle as possible that doesn't kick down a gear until you need it. Using this technique I climb most hills in 5th, and only have to use 4th near the top of the really steep ones. If it needs 4th then I back off a bit and cruise up at around 60.

The savings on a 500 mile tow is about $40. That buys a lot of beer.