My 2012 GMC Sierra

[nds1968]

2012 GMC Sierra Ext Cab SLE
Vortec 5.3L SFI Engine
6-Speed Auto Transmission
Summit White w/Ebony

[nds1968]

It is equipped with:

POWER TECH PACKAGE
VORTEC 5.3L V8 ENGINE
W/ACTIVE FUEL MANAGEMENT
6-SPEED AUTOMATIC TRANSMISSION
LOCKING REAR DIFFERENTIAL
TRAILERING PACKAGE
ALUMINUM WHEELS
HEAVY DUTY COOLING
AUTO DUAL ZONE AC
BLUETOOTH FOR PHONE
CD PLAYER WITH USB PORT
STEERING WHEEL RADIO CONTROLS
PWR SEAT ADJUSTER - DRIVER
6 WAY
FOG LAMPS
LOCKING TAILGATE
EZ-LIFT TAILGATE

CONVENIENCE PACKAGE INCL:
UNIVERSAL HOME REMOTE
ADJUSTABLE POWER PEDALS
REMOTE VEHICLE STARTER SYSTEM
REAR PARKING ASSIST

ON THE JOB PACKAGE
SKID RESISTANT BED LINERS
BED RAIL PROTECTORS
BED MOUNTED TIE DOWN HOOKS

POWER REAR SLIDING WINDOW
INTEGRATED TRAILER BRAKE CONTROLLER
17" ON-OFF ROAD BW TIRES
REAR AXLE, 3.42 RATIO
7,000 LBS GVWR

OFF-ROAD SUSPENSION PKG INCL:
OFF-ROAD SKID PLATES
HIGH CAPACITY AIR CLEANER

[yote1234]

looks great... i just bought one yesterday .. 2012... extendedcab as well. i like the 5.3 and 6speed.. nice truck

[piecesparts]

When I bought my 2011 GMC, I found that the 93 MPH cutoff had to go. I now have changed that to a point that it does not interfere with the operation of the truck. The 5.3, with a six speed tranny is a good mix. A set of headers awakens the monster in the engine. Mine is a standard cab truck.

[nds1968]

Hey thanks. The truck has plenty of power for me and I am getting use to the 6 speed. I bothers me some times how it downs shifts. I have 1,400 miles so far and I like the truck but I hope the millage improves. I am only averaging 13.8 MPG

I'm only adding a few bolt on items to the truck. Vent visors, oval tubes, mudflaps, under seat storage tray, and I just ordered a Rough Country 2" leveling kit for the front Nate

[yote1234]

Originally Posted by nds1968

Hey thanks. The truck has plenty of power for me and I am getting use to the 6 speed. I bothers me some times how it downs shifts. I have 1,400 miles so far and I like the truck but I hope the millage improves. I am only averaging 13.8 MPG

I'm only adding a few bolt on items to the truck. Vent visors, oval tubes, mudflaps, under seat storage tray, and I just ordered a Rough Country 2" leveling kit for the front Nate

just ordered the under seat storage... nice!

[nds1968]

Originally Posted by yote1234

just ordered the under seat storage... nice!

I bought the Husky brand and it's a very nice piece I just ordered the rear wheel well liners also I'm thinking about changing my door handles to the painted style.

[trendkill]

Where did you guys get the under seat storage?

[2013_GMC_BLACK_SLT]

Originally Posted by nds1968

Hey thanks. The truck has plenty of power for me and I am getting use to the 6 speed. I bothers me some times how it downs shifts. I have 1,400 miles so far and I like the truck but I hope the millage improves. I am only averaging 13.8 MPG

I'm only adding a few bolt on items to the truck. Vent visors, oval tubes, mudflaps, under seat storage tray, and I just ordered a Rough Country 2" leveling kit for the front Nate

I'm averaging only 11.5mpg with my '13 GMC SEIRREA SLT. A ways off from the sticker of 17mpg. Considering Headers w/High Flow Cats. made a difference with my 2005 GTO, almost 2mpg and 28HP at wheels. Anyone in here know if this would be the same with the LQ block compared to my LS in the GTO?

[piecesparts]

I get 19 MPG average with my 2011 2wd SWB, but your 4wd will affect that some. I had the 6 speed shift points modified when I did my computer tune. I did not like the overlap sensation from the downshifts and I wanted it to shift faster than it did from the dealer. I really like the setup, now.

[dishow]

I like it. just ordered oval bars and bed liner for mine. Thanks for the pics. Nice truck.
Posted via Mobile Device

[Dalaigh]

11.5mpg? I'm getting 16mpg in my '12 with a 4.8 and 4spd. I thought the 5.3/6spd was supposed to be better.

[2013_GMC_BLACK_SLT]

Me too. Called GM Hot line. Phone idiot said wait until after break in. I asked what do you consider break in period. response was 5,000-7,500 miles. I said ok I guess I will just buy a gas station until then.......not to mention I would have ordered the 6.0 liter at that point.

[piecesparts]

My 5.3 in my 2011 started at 18 to 19 MPG and it is still in that area. Standard cab, SWB, 5.3, 6 speed auto, 3.42 gears with 20" rims. I did a EFI Live tune and put headers on, and the mileage is still around 19 MPG UNLESS it is really cold outside, then it drops.

[2013_GMC_BLACK_SLT]

I also have 3:42 gears which should be a + for gas mileage. The first two tanks I even eased my foot on the gas like the pedal was made from egg-shell. All my friends at the race track have 5.3's that they tow their enclosed trailers with. They tell me they are getting 11 with a trailer.......I sure hope there is something true about the break in period before gas mileage gets better or I will be regretting not going through with the deal on the FORD w/ECCOBOOST. Thanks for the input on your truck.

[Dalaigh]

Originally Posted by 2013_GMC_BLACK_SLT

I also have 3:42 gears which should be a + for gas mileage. The first two tanks I even eased my foot on the gas like the pedal was made from egg-shell. All my friends at the race track have 5.3's that they tow their enclosed trailers with. They tell me they are getting 11 with a trailer.......I sure hope there is something true about the break in period before gas mileage gets better or I will be regretting not going through with the deal on the FORD w/ECCOBOOST. Thanks for the input on your truck.

The Eco-boost isn't getting anything anywhere near what Ford is claiming. A friend has one and he's regretting shelling out the money for 15mpg. Sure he's got more power then my 4.8, but we tow the same thing, and I paid close to $15,000 less. And those turbos are going to be a fortune to repair when they go.

[2013_GMC_BLACK_SLT]

Yea....TURBO'S X2....ouch

[piecesparts]

Originally Posted by 2013_GMC_BLACK_SLT

I also have 3:42 gears which should be a + for gas mileage. The first two tanks I even eased my foot on the gas like the pedal was made from egg-shell. All my friends at the race track have 5.3's that they tow their enclosed trailers with. They tell me they are getting 11 with a trailer.......I sure hope there is something true about the break in period before gas mileage gets better or I will be regretting not going through with the deal on the FORD w/ECCOBOOST. Thanks for the input on your truck.

I agree, the people that I know that purchased the Ford Ecoboost setup are really put out that their mileage is worse than mine. I have good gas mileage and plenty of power in my setup. I would really like a 3.73 gear, but it would curb my highway m,ileage too much. When we did the computer tune, we also closed up the shifts in the transmission computer. There is a lot of slop in the shifts and it allowed for too much tranny flare issues. in other words it would take too long to go from one gear to another.

[nds1968]

Well I have about 4800 miles on the truck now. I am averaging 14.8 MPG city driving.

I don't have any plans on modifying the truck mechanically at this time. All my expendable money is being spent on my 67

[2013_GMC_BLACK_SLT]

Originally Posted by nds1968

Well I have about 4800 miles on the truck now. I am averaging 14.8 MPG city driving.

I don't have any plans on modifying the truck mechanically at this time. All my expendable money is being spent on my 67

I can live with 14.8 but this 11 crap has to go......

[orange 69]

Originally Posted by nds1968

Well I have about 4800 miles on the truck now. I am averaging 14.8 MPG city driving.

I don't have any plans on modifying the truck mechanically at this time. All my expendable money is being spent on my 67

I owned the exact same truck as you except it was 4 door and my millage never improved (never got over 15 mpg) I loved the truck though so I just got over it

[piecesparts]

That Z71 package is killing you.

[Gus350]

What package would get the best gas mileage then I'm about to buy a new truck 4 door GMC.

[nds1968]

Originally Posted by piecesparts

That Z71 package is killing you.

How is the Z71 package killing the gas millage?

[piecesparts]

Originally Posted by nds1968

How is the Z71 package killing the gas millage?

Z71= 4 wheel drive= lower MPG. The average gas mileage on the new 4 Wheel Drive trucks appears to be around 15 to 17 MPG. Where the mileage for the 2WD trucks averages around 19-21. Unless you are going to the mountains, working in the country, or really driving in deep snow, the 4 wheel drive provides more pain than success. I have been driving 2 Wheel drive trucks for many years, now and I am very comfortable with my mileage and the fact that I get around as well as most 4WD trucks on the icey highways of Kansas. I am by no way knocking a 4WD, but in the long run, the mileage and wear on the extra drive components is costing the owner much more, unless he really has a need for the extra driveline.