The gasser super duty trucks will tow anything the diesel ones will. It's just the preference of the driver, not really a black and white ink on paper kind of decision. This is why gas vs. diesel threads go on for weeks......

I drove gas engines for years, I tow medium to large trailers all the time. If I put 50k miles on my truck in one year, 40k of those miles will be with a trailer. So for me the diesel is extremely nice. When you drive with a good load/trailer the engine does not rev high, make louder sounds, and the transmission is not searching for gears every 30 seconds. Generally, the diesel will not act any differently when it has a big load pulling against it.

With a gas engine there is much more evidence apparent to you that the engine is being asked to work hard. I find this annoying, tiresome, and even stressful. I drive around 1,000 miles per week and prefer not to listen to a screaming engine.

So in my personal experience it boils down to perception. The gas motor lets you know when it's working. The diesel remains the same, loaded or not. It's more enjoyable and more powerful.

For what it's worth, I don't pay any attention to the bad fuel fuel pump threads anymore. I don't even read them.

Hope this helps.