2014+ Gas Mileage (MPG) Topic

Cap'n Pete · January 16, 2014

My mileage so far seems to be all over the map, but so has the temperature around here! It's been hard to determine at what SPEED the mileage is the best, because it's not always consistant. Sometimes it seems to be right around ~60 mph. Other times, I can get just as good sitting at ~75 - 80 mph.

The average mileage since I've owned the truck (just over a month, and about ~1000 miles) is only around 12.5 MPG! HOWEVER, it's been a DAMN COLD winter so far, so I've been making lots of use of the remote start, and most of my driving is city driving, as well as towing my sled around a couple times, so really NOT getting the best the truck has to offer.

That being said, my best 50km (sorry, ~25 mile) average was just shy of 20 MPG (around 19.75 MPG). I'm pretty happy with that. I can see the potential this thing's got. The few days the temperature has been ABOVE the freezing mark, the mileage improves substantially. I'm looking forward to warmer weather and summer fuel ...... will probably have no problem clearing the 20 MPG mark on a regular basis then, and probably at ~75 mph.

Johnnymac · January 17, 2014

I have 1100 miles on mine and the best I've got on the highway is 18! My average is 13.8. Definitely not what I was hoping for. I hope it gets better because I don't see much improvement from my 2012. I have 3.42 in mine with 22'' factory wheels but I had 24'' wheels on my 2012 and got about the same it had a 3.08

Ron.s · January 17, 2014

6.2; 3.42 gears and 550 miles when I left on a 650 mile trip...freeway driving. Posted speed limit mostly 75 but some 65 and maybe 200 miles of 80 mph. Drove 5-8 over speed limit with trip average of 81.5 MPH. First tank average 17 and second tank 18...more up hill 1st tank, down hill 2nd tank. Fair amount of hills with elevation changes of 3500', start and end same elevation of 2800'. I was very pleased with results! In cruise control I pulled most 5-6% grades in 6th gear but one very long grade it shifted down to 4th gear at 85MPH set speed. I think it will pull any 6% grade at a lower speed of 75. I am running studless snow tires, Michelin X Ice 20's but low rolling resistance so may not hurt mileage.

But not so good in town driving, it's hard to hit 14 for an average....more like 13. My AFM is rarely in V-4 mode, although the engine has the torque to run V-4 a lot more. I think GM dialed it back for some other reason: exhaust overheating or engine lube come to mind.

LTZTom · January 18, 2014

6.2; 3.42 gears and 550 miles when I left on a 650 mile trip...freeway driving. Posted speed limit mostly 75 but some 65 and maybe 200 miles of 80 mph. Drove 5-8 over speed limit with trip average of 81.5 MPH. First tank average 17 and second tank 18...more up hill 1st tank, down hill 2nd tank. Fair amount of hills with elevation changes of 3500', start and end same elevation of 2800'. I was very pleased with results! In cruise control I pulled most 5-6% grades in 6th gear but one very long grade it shifted down to 4th gear at 85MPH set speed. I think it will pull any 6% grade at a lower speed of 75. I am running studless snow tires, Michelin X Ice 20's but low rolling resistance so may not hurt mileage.
But not so good in town driving, it's hard to hit 14 for an average....more like 13. My AFM is rarely in V-4 mode, although the engine has the torque to run V-4 a lot more. I think GM dialed it back for some other reason: exhaust overheating or engine lube come to mind.

I'm glad I waited for the 6.2L after reading your post. My '07 5.3 got the same mpg. I wasn't sure what the "real" mileage would be but was pretty sure the posted mpg ratings were bogus. I can live with what you're getting.

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thehad · January 21, 2014

Been a while since I posted anything but I just made a trip today and got the best gas mileage in any truck that I have owned. I made a 214 mile trip with a moderate tailwind of about 12 - 16 mph and outside temp of 70 - 80 F and got 26.1 mpg with the cruise set to 70 mph. I don't remember what my best 25 and 50 mile were but I think the 25 was 30.2 mpg and the 50 was between 28 and 29 mpg. I just broke 13000 miles on my truck on this trip as well. My city mileage is not that great , averaging 14 mpg, but I also have a lot of short trips and very little freeway driving during the week. Overall, I'm very impressed with these new trucks' fuel economy.

WhiteMike · January 21, 2014

Any numbers with the 6.2 with the 3.42 gears and 4x4?

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james83 · January 21, 2014

You guys seem to be getting way better MPG than I am. I do 90% city driving and have a lead foot . I'm averaging around 12-14 MPG. I use premium gasoline. Have the RC 2" level and 275/60/20 Cooper Zeon LTZ tires. Front air dam is still installed. For reference, when I dropped my truck off for the fire recall, they gave me a 2WD SLE loaner. DIC said average MPG was 16 something. I reset Trip A and while I had it, the average MPG was 14. Not much better than my leveled 4x4. So I think my poor MPG is more a factor of the driver... I don't how you guys can get 16-20. I would get run over driving like that around here.

8KCAB · January 22, 2014

1300 miles here. City driving with mix of surface streets and highway. City is pretty hilly, but I'm pretty gentle on the gas. Been averaging 15-16mpg. A little dissapionting considering my last truck was getting about 17-18 city.

MD2014 · January 22, 2014

Any numbers with the 6.2 with the 3.42 gears and 4x4?

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Corpus Christi to Austin Texas: cruise set at 70mph. I averaged 19.6mpg. The route I take has many small hills so v4 did not activate as much as it normally does on flat highway stretches.

I am now averaging around 17.8mpg with 70% farm roads and 30% city driving.

Running premium fuel as well.

Dnt · January 23, 2014

2014 GMC Sierra Crew Cab Z71 4x4 3.42 gears bed tonneau cover. approx 1300 miles 15.8 average and 20.6 best shows on DIC. mostly highway miles at higher speeds 75 to 85. Used one tank of E85 fuel which may have skewed it a bit all other has been regular unleaded at 87 octane. I traded in a 2009 GMC Sierra Crew Cab Z71 4x4 3.42 gears (bed cover tonneau cover was transferred to this one at dealer new truck had less than 10 miles on it) Now old truck was not flex fuel so I never used the E85 but always ran the regular 87 octane and it showed a average over 87k miles of 18.1 Hopefully this 2014 will do better I am basically driving the same routes at the same speeds as before so I EXPECT at least 18.1 dang it. I will have to do a manual test to check the DIC accuracy but I think it is probaly pretty close my old truck was always within 1 mpg when I manually checked it. Now one thing on the old truck it was an oil burner, it used a lot of mobile1 motor oil so maybe that was really helping the fuel mileage LOL. I see a lot of people on here claiming over 20 mpg I want some of that but do not want to drive like a granny out there either.

Edited January 23, 2014 by Dnt

New2GMC · January 23, 2014

I have about 500 milers on by my own driving and the truck has 900. I noticed a few things . In auto 4x4 I'm getting about 11 mpg around town. I didn't pay attention in 4x4 high. I do think 4x4 high works better than 4x4 auto but I don't have the snow plow on now with the 4x4 auto. My overall mileage on trip B is @ 16mpg and trip A varies depending on where and the speed I drive. The longer I leave the trip A without resetting the lower it goes. So I think resetting is giving everyone a false feel for real MPG.

Bikewhisperer · January 24, 2014

I've been checking my hand calcs against the DIC and they are surprisingly damn close. I not happy with my fuel consumption at all though. I have been making it a mission to beat my best records on the DIC by basically driving like an old lady everywhere I go for the last while, and I mean seriously babying it, and I can't seem to get anywhere near the numbers I am seeing some people getting. SLT 5.3 with the 3.08 gears.

A little more than 50% of my daily driving is highway rarely over 65. The only time I can get my numbers down is on the freeway at 50, then the instant is great! There has been some crazy cold weather (-30 and colder) but alot of nice above freezing days as well. Usually parked in heated garage so warming up is minimal.

12.02 First fill

16.63 highway trip at 60-75mph

11.94

12.39

12.24

7.64 towing 2000 pound enclosed trailer in a blizzard on highway, high side wind.

14.84 good highway conditions at 65

14.53

14.24 started with premium from here on

13.42

12.91

14.95

15.75

13.71 Most recent 5444kms

Average lifetime 13.28 mpg or 17.71 l/100kms (17.4 lifetime according to onstar) 5444kms on vehicle

Best ever 25 mile 18.52 mpg ot 12.7 l/100kms

Anyone else from the cold north getting numbers this low? I expected a hell of alot better.

irondaddy · January 24, 2014

I have a New.. under 1k 5.3L silverado stock, and got a best 20.5mpg and haven't seen it since. My in town on 4 auto is around 9, and my avg on 2w is 12-14. I tried babying it a bit, and goosed another mpg or 2 but no better.

TimmyG · January 25, 2014

My 11 my mpg went up and up till about 6,000 miles

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VMaxtastic · January 25, 2014

I've been checking my hand calcs against the DIC and they are surprisingly damn close. I not happy with my fuel consumption at all though. I have been making it a mission to beat my best records on the DIC by basically driving like an old lady everywhere I go for the last while, and I mean seriously babying it, and I can't seem to get anywhere near the numbers I am seeing some people getting. SLT 5.3 with the 3.08 gears.

A little more than 50% of my daily driving is highway rarely over 65. The only time I can get my numbers down is on the freeway at 50, then the instant is great! There has been some crazy cold weather (-30 and colder) but alot of nice above freezing days as well. Usually parked in heated garage so warming up is minimal.

12.02 First fill

16.63 highway trip at 60-75mph

11.94

12.39

12.24

7.64 towing 2000 pound enclosed trailer in a blizzard on highway, high side wind.

14.84 good highway conditions at 65

14.53

14.24 started with premium from here on

13.42

12.91

14.95

15.75

13.71 Most recent 5444kms

Average lifetime 13.28 mpg or 17.71 l/100kms (17.4 lifetime according to onstar) 5444kms on vehicle

Best ever 25 mile 18.52 mpg ot 12.7 l/100kms

Anyone else from the cold north getting numbers this low? I expected a hell of alot better.

Im averaging about 14 MPG's right now.. Only have about 700 km on it though, mostly highway.. Some gravel roads, some city, and some in auto 4wd... So my numbers are pretty skewed. And you know about the winds out here haha. My '13 6.2 was better on fuel, this thing is a 5.3 with 3.42's

Edited January 25, 2014 by VMaxtastic