Diesel has more energy content even after tinkering by the EPA.
Diesel engines are built much heavier than a gas engine because of power output. The EPA has done a lot to neuter diesels but they still put out more power. You can generally increase the torque, the ability, to pull a lot, of weight, up a hill by cranking up the boost until you melt the pistons.
The reason eighty thousand+ lb Semis run diesels is the torque and reliability.
Many diesels exceed a million miles before first rebuild. Diesel p/u were built to exceed 300,000 miles before major rebuild.
EPA taking sulfur out of diesel greatly diminishes lubricity. We will see how that affects diesels in a few years.
If you can find what you want in a MH built before 05 when they put cats in the mufflers and increased operating temps of diesels go for it. Be prepared to keep lubricity improvers in the tank but you avoid all the emissions garbage.