Hey all new to the forum. I currently own a 2017 2500 Dodge with the 6.7 cummins, its "weight lossed" and has some good stuff under the hood/trans.

I average about 50,000km (35,000 miles)/year, i tow about 12klbs 24x a year in the summer and its all mainly flat country roads or highway, some small hills. Currently daily driving im doing about 12L/100km (19.5mpg) unloaded and 16.5L/100km (14.5mpg) loaded.

Ive been offered a VERY nice 2014 Denali 2500HD with the 6.0 L96 and 6l90e trans. Has anyone been in my situation and built a turbo ls tow pig before? How reliable are they? How bad is the mpg? How bad is the cost of running/owning one? Did you notice a big difference towing between a diesel/gas?

I do all my own work on my trucks and have a limited but reasonable budget to put a turbo truck together.

Any and all advice appreciated.

 

There's @RDF1 that has a similar turbo GMT800 2500HD. I don't believe he's active here anymore, but you can ping him on the SilveradoSierra forum. He's posted mpg values of his truck before.

Good luck.

 

Simply put, you’ll get half the mileage unloaded or towing and it won’t tow half as good as a diesel.

 

Ive had a bunch of issues trying to get logged back in on this site for whatever reason. Most the times it wont even give me an error it just sits there like its confused when i click Log In.

Anyway,
I replied to him on the SS forum.

The newer diesels dont get that great of mileage towing.
On our recent trip to Florida for storm work mine got within 2mpg of my buddys 2020 3500 Ram and his cousins 2022 F350 But my neighbors old 2000 ram 5.9 CTD / Manual 3500 got the best by a few MPG.
And for towing Its not that much different Ram was 12mpg, F350 was 11mpg, old 5.9 was 15mpg and mine was 10mpg. Plus i had 70 gallons so i could go further than they could without refueling. They didnt know i had an extra tank so it was puzzling to them hahaha. Fun times.

The only big difference is the diesel makes max torque under 2000rpms where the gasser makes peak torque at 4000-4500rpms.
But whats funny is the diesels with automatics wont ever see that max torque but in 1st gear for a split second. While at speed (70mph) if engine is under a load it downshifts and rpms rise to peak HP and not use the Torque down low.

 

I replied on SS as well but I didn't realize you were coming from the Cummins. I would keep the Cummins.

 

2017 cummins would be hard to beat for towing 12k on the regular (ps: i have an '18)
my answer would be an easy NO because GM stopped making manuals after 2006... but that's just me.
even daily driving, my 8000lb dodge still gets the same or better fuel mileage as my built 5.3 1/2ton that only weighed 4800lb.

 

Plus, the diesels are way nicer to drive with a load bc they aren’t at 4k+ rpm’s the entire time at 70 mph.

 

... to be fair, though, my cummins at 2500rpm feels like it's working as hard as a small block at 4500

 

Yea id rather not deal with diesel issues. The repair cost on them is crazy.
I tow more with my gas burner than all my buddys do with their diesels. Fuel mileage isnt that big of a deal for me since i dont drive it all the time.
Just deleted my buddys F250 and his now gets 22mpg which is nice but towing it doesnt get that great of mileage. And with cost of fuel its cheaper for me to tow since gas is $1 cheaper a gallon than diesel. Even the strawberry diesel is still expensive.

 

in all fairness, towing more or less than other guys don't really affect your question of which would make for a better tow rig. just throwin' that out there.
when you also factor in that towing with a turbo gasser on 87 octane is asking for trouble... and most places i've seen, 91/93 is roughly the same or higher price than diesel... fuel cost works better for the diesel because it's getting better than 9-10mpg.

pulling heavy repeatedly: diesel won't work as hard & would be more reliable in the long term
gasser (especially boosted) will have lower fuel mileage
diesel costs more to maintain & repair
night & day difference in how much easier a diesel tows... not that a turbo gasser is horrible, but there's definitely a difference. mainly due to the driveline setup required to use appropriate RPM ranges for each engine. that & the diesel transmissions are geared differently with closer ratio spreads.