Newbie, About To Buy 2011 Sierra, Number Real World Numbers On Mpg

crouton · January 7, 2011

I am looking hard at a 2011 Sierra, regular cab, 4x4, with a bunch of extra options....ordered from the factory to my specs.

Walking through the lot, the 2011's with the 5.3 have 20mpg city, 30mpg highway on the window stickers (this is in Canada if it matters).

Is this a realistic number I can expect to achieve?

Also, what is this talk of gmt-900, gmt-700, I know your not talking about time zones...so, help.

MikeNH · January 7, 2011

There are some threads in the fuel economy section about real world numbers (realize most are the silly gallons we use here in the US though and not real gallons ). As got the GMT stuff- that is the code for the GM truck generations- GMT400 is the 88-98 trucks, 800 is 99-03 and 900 is 07-current. K2 is the next generation truck, due in 2013-14 depending where you look.

jdubub · January 7, 2011

hello and welcome Mine is a 5.3 with the 4 speed tranny. I average 16.9mpg with half the time in stop and go traffic the other half highway

longhorn_giant · January 7, 2011

I average 18.3 with the 5.3 and 4sp tranny

music · January 8, 2011

I've found the sticker numbers to be about right for "good" driving conditions, but you can easily kill them away by driving harder or faster.

brianf60 · January 8, 2011

my 4.8 eats 17 liters per 100km average.

rogerf · January 8, 2011

I am looking hard at a 2011 Sierra, regular cab, 4x4, with a bunch of extra options....ordered from the factory to my specs.

Walking through the lot, the 2011's with the 5.3 have 20mpg city, 30mpg highway on the window stickers (this is in Canada if it matters).

Is this a realistic number I can expect to achieve?

This sounds like an update of what I got in '07...Reg cab, 5.3L, 4-spd, 4X4, 3.73 diff ratio will go 20 mpg (US) on the highway on a good day with cruise control running the posted speed limit. I have run 600+ miles on the larger 34 gal fuel tank. Most of the time the DIC is showing @ 17 mpg. Personally find the 5.3/4-spd has more than enough power. Maybe the 6-spd, 3.08 diff, and smaller engine is just as drivable with better mileage. Options to consider if buying spec order...electronic transfer case, locking & spring-loaded tailgate, and DIC is worth every penny.

b00001 · January 8, 2011

I am looking hard at a 2011 Sierra, regular cab, 4x4, with a bunch of extra options....ordered from the factory to my specs.

Walking through the lot, the 2011's with the 5.3 have 20mpg city, 30mpg highway on the window stickers (this is in Canada if it matters).

Is this a realistic number I can expect to achieve?

Also, what is this talk of gmt-900, gmt-700, I know your not talking about time zones...so, help.

I am in sales and on the hwy every day. I have yet to hit the "Sticker Number". I have come close a couple times with 20.1 and 20.3 MPG, but not the 21 listed on the sticker. I have had a 2009 and now this 2010, neither has hit the number. I have gone through many vehicles and I always best the HWY numbers. I am a little upset that I have not been able to even meet the numbers on 2 trucks. I even spec'd my current ride out to maximize fuel economy: 3.08 rear, lighter ext cab instead of crewcab, put a tonneau on and drive it very "softly".

TheGreekIndian · January 8, 2011

On chevy's website is says crew cab 5.3s are rated at 18 mpg. the LTZ is the only truck rated at 21 MPG HWY for some reason...the EPA stickers were spot on with my old G6 GTP and my Cobalt SS, but they did a good job miss leading consumers on this one!

from Chevrolet.com's site.

Shu · February 7, 2011

On chevy's website is says crew cab 5.3s are rated at 18 mpg. the LTZ is the only truck rated at 21 MPG HWY for some reason...the EPA stickers were spot on with my old G6 GTP and my Cobalt SS, but they did a good job miss leading consumers on this one!

from Chevrolet.com's site.

I think that chart shows the LT with 4.8 and 4sp auto not the optional 5.3L with active fuel management and the 6 speed auto like comes standard on the LTZ.

NickS · February 7, 2011

I think you are all crazy. 18mpg on hwy (maybe 55mph and downhill) and 14.5 city. I have mixed driving (70% hwy and 30% city). On the highway, I do run about 70-75mph. Every tank I run through reads out 14.7 mpg. Even on road trips where I take it pretty easy, best I have ever got was 18.5. I have had 6 trucks since I started driving, and none of them have got close to what the sticker advertises.

music · February 7, 2011

I think you are all crazy.

That's probably a true statement, but my mpg is pretty good. I've measured on numerous long trips, and always average 19.5+ hwy (usually right at 20). That's in warmer temps and relatively smooth terrain @ (limit + 5 mph). If it were 10 degrees outside, I'd expect that to drop a bit. Cold and stop/go kill economy on a 6k lb truck.

HawkScot · February 7, 2011

On our 2008 Yukon XL Denali, we get better mileage when running premium fuel (it runs fine on regular, but gets better mileage and has more power on premium). I think the quality of gas is a big factor, I think that the 10% ethanol reduces mileage. We have gotten as high as 19.8 mpg, loaded with family on vacation, no winds, cruise on 65/70 most of the way.

I have been with friends that complain about mileage and they accelerate gently, but they do not slow down ahead of time, instead stopping hard all the time...

TheGreekIndian · February 8, 2011

500 miles on my truck and going 70 mph i got 17 mpg. In the city without going higher than 17 rpms I only getting 11 mpg. Hopefully much better after break in is over with.

fred walters · February 12, 2011

I have a new 2011 1500 gmc sierra all terrain with a 5.3 with AFM. After 1500 miles, most around town, I am at 11 to 14 mph. I checked the gmc website and there is no truck with 30mpg. Even the hybrid is 20/21.