Settle an argument for me, please!
My buddy and I have been arguing over this for a few weeks and I keep telling him that he is wrong about this. He says that I should not drive with the tow-haul on all the time because it hurts my MPG...
Forum Discussion
ferndaleflyer wrote:No you are not wrong, however tow/haul mode means different things to different transmissions. In your specific case, it locks out overdrive, as your truck is geared to purr along at a super low RPM, to get better mileage. An RV is not geared that low to begin with, so tow/haul mode doesn't need to shift out of overdrive, however it does change the shift points.
I have 2 Fords and if in OD and hit the TH button going say 60mph it will shift out of over drive and the rpm will increase. I would assume that more RPM means less fuel mileage.....could be the reason it gets 17mpg without the TH engaged and 15mpg when it is.....Am I wrong or is there some other reason the mpg changed. This was on a 350 mile each way trip towing nothing.
There probably is a cruising speed that tow/haul mode would cause it to downshift, but apparently not at the speed the OP drives. SO the only negative is the increased pump pressure, which does hurt the mileage, but not by enough to easily prove it. (That is why everyone keeps saying it won't change it, even though it will, by a very small amount)
