I guess a lot of it comes down to what you are pulling. I have a hemi and it pulls a couple mowers just fine, but it struggled to pull 6k up hilly roads (can't blame it). I pulled twice that up the same road with my diesel. Then I got into spraying. I put a 100 gal sprayer in the back of my 1500 and when I filled it up, the rear end was almost on the ground. The diesel doesn't even notice the full sprayer and a trailer full of mowers and tools. I don't just cut grass, I do lots of landscaping so I have to pull a decent bit of weight sometimes. I won't own any more gassers for a while because of this. The hemi is a good engine but it wasn't made for what I need to do. Add all of the other factors in, but pretty much any hauling calls for a diesel.