well then, thank you, one more reason I have discovered to justify my dislike of big three vehicles.  BTW,,, a stealership told you that to get out of a warranty repair.. And the big three wonders why sales are down,, way down..

Agree about the RPM's for sure….All I know is ruined a Ram p/u tranny towing a not real heavy trailer a few hundred miles, dealer said it was towing with OD on…….Merry Christmas!

Jim[/QUOTE]

OK, haven't heard back from you on this one. You stated some really good things about a new drivers mastering/learning new skill sets when on or off pavement. I agree completely. I spent the better part of 2 or 3 years "learning" how to drive off pavement. That proverbial learning curve gets pretty sharp when it begins to affect your wallet because of breaking things. That was 40 plus years ago and we had to figure it all out on our own. Fortunately, on and off pavement I was a quick learner and eventually became a "safe driver" instructor for a major corporation.  In a manual shift automobile it doesnt' matter what gear you are in as long as it is in the "sweet spot". With gasoline engines that sweet spot is somewhere between 1800 and 2400 RPMs depending upon the engine specifications.  A comfortable cruising speed say 65mph is a good way to find the center of that sweet spot.  With modern diesel engines that sweet spot is between 1400 and 1600 RPMs.  A good driver will manually downshift before the engine begins to bog down in order to keep the engine RPMs in the sweet spot. The ideal scenario is to operate the engine at the lowest RPMs possible in order to do the job. A gasoline engine is operated correctly in the same manner except of course the RPMs must be maintained at a higher level. Diesels are much more torquier at much lower RPMs, but the goal remains the same for both. Efficiency. An automatic transmission does all the thinking and all the work for you, except when it may be better to manually downshift an automatic to control speed while on a decent instead of using the brakes.  If one is crossing the great plains one figures out pretty quickly how to mimic the behavior of an automatic transmission. 5th gear/(overdrive) on the descents and flats, and dropping to 4th gear to pull the ascents.  As stated, it is all aboout keeping the RPMs of the engine in the sweet spot..  Thank you Jim and have a Merry Christmas !!

To each his own on overdrive but I think most vehicles can get damaged by using the OD while towing…..I would see what the book says…..

Jim

OK,, I give up, I'm puzzled.  Why turn the Overdrive off when pulling a trailer?  I like getting 14-15mpg on my way west. It downshifts all by itself at the proper time to maintain the RPMs in th peak power band and I  downshift manually to control downhill speeds.  With a stick shift of course, the driver must do this manually, which I did for over 45 years.  I was very stubborn about switching to an automatic but have since changed my mind. Change my mind.  🙂