Fuel Economy of 2014 Sierra 6.2 Max Tow.

OmahaBen · October 30, 2014

2014 GMC Sierra SLT 4x4 6.2 Engine, 3.73 Gears, Crew Cab Regular Box

I have about 1800 miles in the truck in about two weeks time due to some out of town jobs.

When towing I was connected to my 3500lb Trailer (Scale Verified Weight) My Total Weight is a 9640

The First Trip is the only trip so far at 70MPH speeds without a trailer.

91 Octane used

19.0MPG DIC 443.0 Miles/22 Gallons 20.13MPG Hand Calculated 70MPH Truck only

16.4MPG DIC 123.0 Miles/8Gallons 15.37 MPG Hand Calculated 70MPH 50% Truck only /50% Towing

13.6MPG DIC 247.6 Miles/19.3 Gallons 12.82 MPG Hand Calculated 71MPH 100% Towing

12.5MPG DIC 142.2 Miles/12 Gallons 11.85 MPG Hand Calculated 73MPH 100% Towing

15.8MPG DIC 287.0 Miles/19 Gallons 15.10MPG Hand Calculated 70MPH 15% Truck only/ 65% Towing

14.8MPG DIC 327.7 Miles/23.08 Gallons 14.19MPG Hand Calculated 71MPH 100% Towing

16.4MPG DIC 267.6 Miles/17.14 Gallons 15.61MPG Hand Calculated Commuting Speeds, 15% Towing

I will probably do another post up to about 5000 miles but probably won't do any past that.

The truck is very powerful, Yesterday did the first hard acceration off the line and it broke the tires loose with traction control on.

It pulls very well, I went through the hills between St Joseph MO and Hamburg IA at 2500RPMs and did it with ease. I had to take the cruise off on my old 5.3 2004 Silverado while going up these hills otherwise I saw 4500 rpms. It was a sad time for the 2004.

We probably went overkill with this truck as it has a tow capacity of 11,700lbs however it will do everything we need to do very well.

It doesn't need to shift all the time like my old truck and that is exactly what I wanted.

I have seen higher RPMS with this truck while accelerating hard with the trailer but I was just testing it out. I know it can get out of its own way even though most of the time we do conservative starts and steady safe speeds.

OmahaBen · December 10, 2014

91 Octane used or higher when available

19.0MPG DIC 443.0 Miles/22 Gallons 20.13MPG Hand Calculated 70MPH Truck only

16.4MPG DIC 123.0 Miles/8Gallons 15.37 MPG Hand Calculated 70MPH 50% Truck only /50% Towing

13.6MPG DIC 247.6 Miles/19.3 Gallons 12.82 MPG Hand Calculated 71MPH 100% Towing

12.5MPG DIC 142.2 Miles/12 Gallons 11.85 MPG Hand Calculated 73MPH 100% Towing

15.8MPG DIC 287.0 Miles/19 Gallons 15.10MPG Hand Calculated 70MPH 15% Truck only/ 65% Towing

14.8MPG DIC 327.7 Miles/23.08 Gallons 14.19MPG Hand Calculated 71MPH 100% Towing

16.4MPG DIC 267.6 Miles/17.14 Gallons 15.61MPG Hand Calculated Commuting Speeds, 15% Towing

17.5MPG DIC 122.4 Miles/7.27 Gallons 16.8MPG Hand Calculated Commuting Speeds Truck only

17.1MPG DIC 372.3 Miles/22.9 Gallons 16.25MPG Hand Calculated 76MPH Interstate Truck only

17.4MPG DIC 373.1 Miles/22.06 Gallons 16.91MPG Hand Calculated Commuting Speeds Truck only

16.3MPG DIC 243.9 Miles/16.2 Gallons 15.05MPG Hand Calculated In Town Driving Truck only

14.9MPG DIC 277.6 Miles/19.6 Gallons 14.16MPG Hand Calculated In Town Driving Truck only

16.7MPG DIC 264.0 Miles/17.03 Gallons 15.50MPG Hand Calculated Hwy and towing 6000lb trailer 20% of time

13.1MPG DIC 122.9 Miles/9.81 Gallons 12.52MPG Hand Calculated 50% Commuting/ 50% pulling 3500 Trailer

17.3MPG DIC 327.0 Miles/19.77 Gallons 16.54MPG Hand Calculated 76MPH Truck only

16.8MPG DIC 331.1 Miles/20.66 Gallons 16.02MPG Hand Calculated 75MPH 80%, Town Driving 20% Truck only

4280 is the approximate total mileage at this time of posting this.

To recap

Running Empty 75 mph I get 16-17mpg hand calculated

Combined driving around town and some hwy 15-16mpg hand calculated

Towing 3500lb trailer I get 12-14mpg towing 70mph speed.

I have also noticed that I love the power the 6.2 has and have been enjoying a bit faster starts. That definitely contributes to lower mileage. I am sure I could squeeze out another mpg on the truck only figures with really babying it. Cutting back to 70mph instead of 75 really helps also.

If you are not pulling much I would just get the 3.42 and the 5.3. The 6.2 is a bit much for the duration of town/commuting I do. However for the amount of towing I do, do I really like having the extra power as the truck easily handles what I pull without stressing the truck much.

It would be nice to have the short box as well but you can't add extra box space when you need it. I fill the box up a lot and wasn't really and option for me.

Good luck on your purchase. I hope this helps someone figure out what they want to do.

thetruck454 · December 10, 2014

Nice info, it gives me hope for my new truck.

Tqjunkie · December 10, 2014

Good info thanks,curious as to why you would like the short box is it for the looks or do you find the truck to be to long with the standard box.

nards444 · December 10, 2014

Nice numbers Im curious on the disparity between the DIC and hand calcuation as seems to be 10% or more, less on the DIC. Everything I have read the DIC seems to be pretty accurate these days

OmahaBen · December 11, 2014

Good info thanks,curious as to why you would like the short box is it for the looks or do you find the truck to be to long with the standard box.

It is a marginal difference from my extended cab 1500, however tight parking spots are a lot tougher. If I was to use the truck for a daily driver alone I would get the 5.3 crew cab short box. I need the longer box sometimes.

I truly like the look of the longer bed with the crew cab. I also like the double cab with the 6.5 box. That has a nice look. I think the crew cab with the short box is sort of funny looking but I understand why they do it. Most people drive these as cars and not trucks.

OmahaBen · December 11, 2014

Nice numbers Im curious on the disparity between the DIC and hand calcuation as seems to be 10% or more, less on the DIC. Everything I have read the DIC seems to be pretty accurate these days

Honestly I am not surprised at all. I have always found that the computer on my 2004 1500 Silverado, 2008 Camry and this truck were all off about .5-1mpg.

Someone on this forum was saying this is figured off of injector pulses and that is the reason for the variance. I have always called B/S on the DIC mileage. I always ask people did you hand figure it or computer. They are to lazy to do it by hand, that takes some effort. Plus they reset the trip and say they are getting 22mpg just because they had a tail wind, going downhill and going 65mph.

My second trip meter I have left on since day 1 and never have reset. It says 16.2 MPG average over the whole run. So I am getting roughly 15mpg, towing 35%, Town and Hwy average. I think that is awesome. Sure it would be great if it was 20. Still more power, more room and better mileage than my old truck. I am happy.

peejaykay · December 11, 2014

What is your payload capacity, per sticker? And GVWR?

OmahaBen · December 11, 2014

What is your payload capacity, per sticker? And GVWR?

The GVWR is 7200

Don't see payload capacity on the sticker.

redwngr · December 11, 2014

Couldn't find one on mine either. Haven't got around to calling to try and find out why. (Maybe I'm looking in the wrong place )

calgator73 · December 11, 2014

Any pics of the trailer? Curious about the actual frontal area. The hwy mileage while towing is very similar to my old denali while towing a loaded tandem axle uhaul but your city mpg is better (I only got 12) On my 5.3 nht, the DIC calculated hwy mpg is about 10-15% higher and my city mpg is pretty close to what you're reporting (my back and forth to work is less than 10 miles of stop and go...engine barely gets to temp this time of year.)