I pulled my TJ with 1700lbs of steel stock split between the trailer and bed of my truck on a steel decked car hauler from GR to Petoskey with my 187K+ mile 2005 GMC 1500 5.3L. I wasn't the fastest thing out there but I was able to do 65 mph highway with no difficulty. I got 9.7mpg on the trip which surprised the hell out of me. I see no need for a diesel for what I use my truck for. I used to think I needed a 6.0, turns out the 5.3 is fine. Big trucks are dumb.