Having towed RV's and large boats for the last 53 years with many gas engines and just 2 diesel pickups, I'll only have a diesel engine truck to tow with, PERIOD!
First Diesel was a 6.2L 1984 Chevy truck and while it didn't have the fast acceleration up to 40 MPH of our 3500 7.4L Chevy dually, it had more pulling power over 40 MPH and nearly double the fuel economy pulling or not! Put 168,000 miles on the truck before selling it to a close friend (State Trooper's) son. He drove it doing construction work until the odometer had 497,000 on it and was rear ended in a snow storm by another vehicle and totaled. We had virtually no repairs needed or done to the truck and none to the engine or transmission during the 168,000 we owned it. Yes, back then a diesel engine had a loud clatter but was quite quiet in the cab.
Had several gas engine trucks for towing and for my business after selling the 6.2L diesel but none had near the pulling power of the 6.2 especially when pulling our 27' 268 Sea Ray heavy cabin cruiser out of the water up the boat ramps. Never forgot having the true pulling power at the rear wheels of the 6.2. The gas engine trucks really struggled and screamed just pulling the very heavy boat out and sucked fuel like crazy pulling our RV's.
2nd diesel is the 2004.5 Duramax CC 4X4 LB ruck we still have and wont part with it. Just nicely broken in at 207,000 miles and only one engine repair ever done. A fuel pressure regulator replaced! Excellent fuel economy and more pulling/climbing power than was ever needed, Very quiet inside, incredible reliable, and virtually no repairs needed in 14 years and over 207,000 miles of towing/RV'ing heavy as that's all the truck has ever done and what it was bought for! Truck has NO rust or dent damage and the paint is bright and shiny and the interior still look about like new as we always take care of our vehicles, boats, RV's and homes! Why not!
We always buy and have done for over 35 years now all our vehicles new/ordered and with cash only as we don't like payments or paying of interest! We collect interest! Hands down the best vehicle we have ever owned for personal or business use and owes us NOTHING! Paid for itself many times over just on fuel costs savings and lack of repairs again also.
Was and is the buying of the Duramax engine truck over a smart and wise financial decision over a gas engine truck??? Without a shadow of a doubt! I Will report again when the truck passes 500,000 miles but at nearly 77 years of age presently and still towing RV's a lot, I might encounter a little problem doing it! Need to consult my crystal ball!!!