re: F 250 vs. F 350. What should I be looking for?

You can get a bumper pull for a camp for mid to upper teens.

That depends on the engine. There's a whole lot that goes into where an engine is designed to be happy at. Generally, 70% load is a good number. It's more efficient around 90% usually, but efficiency doesn't equate to longevity.

I'm talking about the entire truck, not just the engine. Sending lots of torque through the driveline is very hard on it, and making torque is hard on the engine. It's running higher cylinder pressure, higher temperatures, with lower coolant and air flow.

Turning the engine up is very good for it when it's working hard. Odds are, it'll burn less fuel also if turned up.

I drive a raptor and im thinking about selling and buying a used f250 or 2500HD diesel. I dont tow much beside a 22' offshore boat and my captain is wanting to upgrade to a 26'. I dont want to pull that with the raptor.

My wife's family has prolly bought 10 plus campers from him. He's a straight forward guy, prices are prices. Jayco makes a good product and great 2 year warranty.

Eta: if it's ever a camper option for 2nd AC, get it!!!

man, have you ever towed 8500 pounds? I really suggest you go hook your eco up to something with that weight and go drive around. Your towing something that weights almost twice as much as the vehicle your in. If it has trailer breaks it will help, but thats still a shite ton of weight. Don't get me wrong, it'll tow at 65 all day long, but go hook that up to a diesel and its like your gasser towing 2500 pounds. Its just a lot nicer to drive.