I think all 3 make good gas trucks. I don't have any experience with the GM 6.0 so I can't comment. I like my 2016 Ram 2500 with 6.4 hemi and 4.10 rear. Here is my first long towing report from a previous thread. Lots of towing info on 6.4 hemi with 4.10 below if you are interested.
I just got back from almost a 2,000 mile trip, which was the first long tow for my 2016 Ram 2500 gasser. I thought some on the gas vs diesel fence might be interested in how well this gasser tows my almost 35' Columbus fiver (tall profile, 13"4" high) which loaded to camp weighs around 12,000-12,500 lbs.
Trip was from Louisiana through MS, Tennessee and Kentucky and then back through Alabama. Almost all of it was Interstate and I towed at 65 mph. For your info, last truck was a 2015 Ram 2500 with the 6.7 Cummins, which was destroyed in the August 2016 Louisiana flood. I have towed the same fifth wheel with both so I can compare.
Let me start by saying it does not tow like the diesel. Yes, it has to shift more because it has less torque. If you want the easiest towing, and the extra $7-8K upfront and potential costlier repairs once the warranty is up doesn't concern you, then just get the diesel. Please diesel owners don't hijack this thread, I'm just trying to give info so people can make decisions. If you tow regularly in the western mountains at high altitudes, just get the diesel.
If most of your towing is in the eastern US and not at high altitudes, this gasser tows pretty **** good. Yes, it tows at 1,000-1,200 rpms high than the diesel, but that's what it was designed to do. With tow/haul on, it never towed in 6th. Towing in 5th (still an OD gear) was about 2,300 rpms and 4th was about 2,800 rpms. On the longer and steeper pulls, it occasionally used 3rd at about 3,500 rpms. It could hold 65+ mph anywhere we went if you want. For the entire trip, I estimate it probably spent about 55% of the time in 5th gear, 40% in 4th gear, and 5% in 3rd gear. Almost all of the 3rd gear was in Tennessee and Kentucky. I will take this to Colorado in the future, but I do know I will have to bring my patience at times on the long pulls through the passes (yes, I love Colorado).
I hand calculated my towing mileage, so here it goes by tank - 8.1, 8.1, 7.6, 8.0, 8.5, 7.8, 7.2, 7.8, 8.1, 8.0, 8.1. Since I like to have close to half a tank, most fillips were between 150 and 180 miles. In the diesel, I would have probably averaged 10.5-11.2 mpg and filled up about every 200-250 miles. The 7.2 mpg tank was against a stiff headwind. Looks to me like the overall average was about 8 mpg. That's about what I thought when I bought the truck. Non towing I get about 13 around town and 16 on the highway.
My truck is rated to pull almost 16K. I don't think that would be fun. But at under 13K or so, it does a good job overall and great for a gasser. I do not regret my decision on this truck. YMMV depending on how you use the truck.
I read a lot of ib516's posts before buying the truck. Overall, I agree with his towing impressions. Hope this helps others in the truck buying process.
