[quote=“JonnyAction” post=61066]
I am defintely interested in hearing what guys are towing with that still get reasonable mpg.[/quote]
I have an '06 Ford F150 w/ 5.4 liter. My open trailer is quite small. As I mentioned before, tires ride under the truck’s canopy. I get 12mpg@ 75mph and 13mpg@65mph. My tows are pretty flat.
The X5 did about 2mpg better, but I never really understood why. The '99 Dodge Ram got ~9mpg.
An issue that is often ignored in considering how well a tow vehicle handles a load, is the length of the hitch. Consider the rear wheels as a pivot point between hitchball and the front wheels. A long wheelbase truck makes it harder for a force, lateral or vertical, at the hitch ball to put a load on the front wheels. Conversely, a long distance between rear axle and hitch ball makes it easier for the hitchball to put loads on the front wheels. Therefore anything you can do to get the hitchball closer to the rear axle is going to improve towing manners.
One of the reasons that the short wheelbase X5 had decent towing manners is that the design of the truck made for a short distance between hitch and rear axle.
I was able to move my hitch ball ~10% closer to the rear axle, call it 2", without much work. All it takes is drilling a hole in the hitch tube, the thing that the ball fastens to, so that you can put the hitch pin in a different location.
IMO there’s limited gains to be found in using mpg to choose a tow vehicle. The amount of energy required to move your rig down the road isn’t going to change much no matter what you choose. Therefore largely the only way you’re going to get better gas mileage is if you alter your driving habits or get a tow vehicle with a fundamentally more efficient engine. Diesel is a little more efficient than gas. Turbo engines are a little more efficient than NA. But neither is going to be so much better that it makes a person jump up and down. Assuming you have a reasonably modern truck in good repair, if it takes X amount of energy to drive to Road Atlanta, you’re just not going to find something that does it 30% more efficiently. Engine technology is too efficient these days for another 30% to still be on the table. I’d argue that anything better than a 15% improvement is marketing.