WillR's right. It's just the running gear and gear ratios that get beefed up/changed in the Ford "F" series. The key is the motor. If you're going to tow anything heavy on a regular basis, diesel is the only way to fly. As for pulling just a beach cat, you can do that with almost anything on four wheels if you stick it on a light enough trailer. However, once you start to push the engine, fuel mileage dives. I used to tow with a Ford Ranger (4-liter 6-cyl with a five-speed). In any kind of headwind, the mileage would drop to 12 or 13 mpg or lower and even in perfect conditions I never got better than 15. My F250 with a 6.0 liter diesel gets 15, or 16 with just the boat in almost any conditions and will get 20 or more on the highway bare-assed (the truck, not me). The Ranger only got 18 mpg on the highway. Plus, the power and wieght of the Diesel makes the boat feel like nothing.