I finally got a hold of one of my sons friends that is in the university, majoring in automotive design. He said the rule of thumb they use is the towing vehicle should equal or exceed 80% of the combined weight of the trailer and the vehicle being towed.
my present tow vehicle is the cummins, it is gutless and struggles pulling the same load. the tows are stressfull and not enjoyable.
both do the job but by the end of the tow i am not a happy camper. i will be selling the cummins and going back to a powersmoke this summer.