Gas Mileage

[tbhuge]

I do very little highway driving. When I first got the truck I was pulling low 9s. Ran a bunch of seafoam through the gas tank and now I average between 10.5-low 11s.

[fsharp]

I keep seeing people on here claiming they are getting 17-18 on the highway and 14-15 in town. I commute 35 miles each way to work everyday that is all highway and have never reset the fuel economy computer in the 18 months since I bought the truck new. With 80% of my driving on a 4 lane highway it still says I am only getting 14 MPG.

 

 

I'm Getting 16.3 thats it, can't get any better! I'm a very light driver as well.

[V8MSY]

I do very little highway driving. When I first got the truck I was pulling low 9s. Ran a bunch of seafoam through the gas tank and now I average between 10.5-low 11s.

 

 

That's similar to what I get running a 2500HD CC with 6.0L and 4.10 gears.

 

With the way prices are going over here it's either going to get converted to run on LPG or sold on for something that does better mileage.

 

ETA: I get better mileage out of a Hummer H2.

[rat454]

I have an 09 CC 2wd 5.3 with 3.42 gears. Driving easy I can get 18mpg driving back and forth to work which is about 50/50 highway/city. Driving like i want to i get around 16mpg. I made a 400 mile trip and got 20mpg. These mpg numbers are all calculated by hand. The trucks computer showed about 1mpg more.

[kjblake40]

In the summer I was getting 14.5-15.5 mpg city and 18-19.5 mpg highway. Dropped 1-1.5 mpg during the winter.

[Mckenzie]

My dads 2000 silverado 1500 2wd got 15 mpg with real heavy driving(donuts,drifting,tire squealing,heavy accelerating) in stop and go traffic/short commuting when i had to drive it

[jmerrill]

Does anyone know why some window stickers show 13/18 and others show 15/21 ?

This is on the 2011 crew cab with the 5.3L active fuel management, AL block, and 3.42 gear ratio.

Looking at the window stickers, I can't see why they are not identical........

[TheGreekIndian]

GM says a 5.3 CC with 6-speed should get with 3.42 ratio should get 18 HWY. EPA is retarded. the 21 MPG HWY is probably a 5.3 AFM/6-speed/ 3.08 ratio Extended Cab that has no options(lighter).

[Blee]

That's my truck. Took a trip to Austin from Houston last weekend. With a little around town driving after getting there I got 16.8 mpg, the computer said 16.3. I topped it off for the drive back and again the next morning. It figured out to be 17.4 mpg, WTH? I drive very conservatively and don't go blasting down the road with my toes curled around the pedal. Very disappointed. I figured at least 20 mpg.

GM says a 5.3 CC with 6-speed should get with 3.42 ratio should get 18 HWY. EPA is retarded. the 21 MPG HWY is probably a 5.3 AFM/6-speed/ 3.08 ratio Extended Cab that has no options(lighter).

[oleozz00]

Have a 2011 Silverado Crew Cab with the 5.3 l. engine and 3.42 rear axle. With about 1200 miles showing on the odometer I drove to Williamsburg, Va. (300 miles each way) and got 20.9 mpg on the trip down and 19.8 mpg driving home. I did not speed or accelerate rapidly. Around home with driving in town but also over some mountains I am getting about 17.1.

[Mckenzie]

Wooohooo hell yea i got 16 mpg today!!!!!!!!

[242tj]

2008 GMC Sierra Crew 4x4 Z71 w/ 5.3L with 2" level kit and 265/70/17. I'm getting average 17.6 mpg. I reset my mpg log from time to time and it has had a low of 16.5 mpg to a high of 19.8 mpg.

[kdixer]

GM says a 5.3 CC with 6-speed should get with 3.42 ratio should get 18 HWY. EPA is retarded. the 21 MPG HWY is probably a 5.3 AFM/6-speed/ 3.08 ratio Extended Cab that has no options(lighter).

 

 

My 09 CC 4wd 5.3 with 3.42's gets 19-21mpg on the highway consistently. If I really watch my speed I have seen 21.5 to 22 on certain trips.

[nick3941sd]

Now I dont feel so bad about what I usually average. I've been getting combined a little over 16MPG with the mods/options listed in my sig.

 

Iam on the fence to get the Zone 3" BL and slightly bigger tires but still dont know if I want to take the hit in MPGs yet.

[maccini]

I have a 2011 1500 5.3L active fuel crew with almost 4k and I get 15 - 15.7 with 60%H /40%C. I'm in MA and it's not flat here. Hills/mountains kill fuel economy. Driving to work (26mi) I get 14.2 mpg (mostly up hill) and I get 18.3 coming home. (mostly down hill) Oh, I also drive 75-80 MPH on average. I do time to time travel 90-100 mph and get 12-13 mpg. I will try driving slower and post my results.

 

I have a Westers hot tune, 3 chamber magna flow knock off from Lous custom exhaust and a truxedo bed cover.