If I were looking at buying a used truck for towing, diesel or gas, I would ask the seller if we could hop in his truck for sale and go for a test drive towing a trailer I brought along. I would tow it over the same route I just towed it over with my own truck. Sort of a direct comparison.
When gas engine people at the pump ask what kinda mileage I get with a Cummins?"I say 9.6 mpg. That is the most I've seen it use."
Changing vehicles for fuel economy reasons only normally has about a 91 year payback so I don't want to be the cause of that kind of rash behavior. :)
