Hey guys , i currently own a 1500 Denali with a 6.2 (gas), I recently.purchased a 24 enclosed car hauler which I use for my quads and atvs(5units)issue I noticed is that it puts a lot of stress on the tranny and the MPG is horrible I am.talking 5-6mpg same as a semi.
With the same truck I pull my 3 spot jetski trailer and I barely feel the trailer
Talking about 7k in weight

My question is it worth the upgrade to a diesel or is that type of stress on the truck expected considering the weight

What mpg.would I be expecting with a diesel pulling close to 10k?


Thanks guys

Wow. That's almost as bad as the old 6.0

Well the difference in price between the two vehicles is what... 15-20k? That's a lot of fuel.

Sure the diesel will get better mileage than the gas job will but with an emissions intact 6.6 you're not going to be very far from single digit territory anyways.

price difference brand new, is 10k

thinking trade in ill be at 20k difference considering the mileage put on this year.

Well, 10k is anywhere from 4,000 to 5,000 gallons of gas depending on your local price.

I'd say keep the half ton you already bought and let it eat. You already took the hit on depreciation once, no reason to do it again a year later. Besides, you still have warranty on the power train. Click on tow haul mode and set the cruise and don't look back.

I'm with Jimmy on this one. Since it's a 6.2 it should be an 8 speed auto right? You aren't putting stress on the trans, it's psychological because it's shifting all the time. The 6.2 isn't a low end torque monster so expect it to carry some rpm under load. It's doing exactly what it was designed to do. How fast are you towing and is it hilly? If you are towing 7k at 80mph don't expect good mileage even from a diesel. The towing capacity on your truck should be around 10k if you have 3.42 or higher gears so you have plenty of breathing room.


For comparisons sake:

I have a 2014 5.3/6speed 4wd crew cab full size bed. With 5 people in the truck and another 300lbs of gear/coolers/tools I got 12mpg at 55mph on rolling hills towing my 5000lb boat this weekend. I get 14mpg on the same roads pulling my corvette on an open trailer (5500lbs but way better aero). I get 12mpg pulling the car at 80mph on the interstate. My truck has 3.42 gears and I've pulled as much as 7k. I've never felt like it was struggling and the trans temp stays locked in at 200°F. Watch your trans temp and use tow/haul mode, slow down just a bit, and let it eat. Corvette guys are putting 800whp+ through that 8 speed and they are holding up beautifully.

This post was edited by FMX_89 on Jun 27 2017 10:00am

thanks for the imput , and yes 8 speed tranny( very clunky if anyone is interested in knowing)

you might be right, but I try to stick no more then 70 mph

The 8 speed does get caught between shifts a lot. It's the nature of the beast. Call the dealer and see if they have an updated flash for your rpm based on your VIN.