Anyone pull a 14k 5er with a gas engine

I do it. My trailer is around 13500. It does o.k. I would not want to go across country with it. I get 10 1/2 solo and 7.9 towing. The hills are the demons on the gas engine.2nd gear and 4000 rpm's will keep me at 50 mph.6 or 7 percent grades are slower but I get there. I only do weekends and a few 1 week trips. I got a great deal 12 years ago and she only has 36000 miles on it right now and can't afford a high priced diesel so I will have to keep her for a long time.If you can afford a diesel then go for it.