Silverado 2011 mileage

We’ve just purchased a 2011 Chevy Silverado 1500 2wd extended cab with vortec 5.3L V8 6-speed automatic transmission. It’s advertised to get 21/15 mpg and we’re only getting 11-12.

We’ve taken it back to the dealer who says there’s no problem. We haven’t had any check engine lights.

Has anyone had a similar problem? Any suggestions?

How many miles on it? You realize there is a somewhat break in period?

Thanks…the Silverado has more than 5,000 miles…that puts it past the break in period, I think.

So you’re getting 11 to 12 where the advertised mileage is 15. That’s pretty close. The transmission should be just getting settled in programming. I don’t see where the concern is. What did you drive before? How are your driving habits between what you used to drive, and this?

The magical MPG numbers are averages, with no particular relevancy if you are a hard driver, drive up hills alot, have a ladder rack on the back, or have a heavy foot.

There is a reason why these are selling cheaper lately. Gasolina es mucho espensivo!

We get a lot of queries about poor mpg, but nobody ever supplies their data. Nor the method of calculation, nor the type of driving they do. In most cases the answers lie in the missing information. And without the info, we can’t help.

If the dealer says there is no mechanical problem with the truck, then I accept his statement. You must assume your truck is giving you normal mpg for whatever you are doing.

the big numbers on my car read 17/21, I’ve averaged 14.5mpg with my driving habits.

We live in the country and do a mixture of country, highway and a smaller amount of city driving. Our other vehicles, including trucks, have had mileages close to their advertised highway mpg. We’re thinking a “computer setting” issue.

Do you use gasoline or E85? How long do you warm up the engine before driving, and do you idle for extended periods of time?

I would agree that driving habits are probably the big factor here. We had a 1990 Ford Aerostar when my son was a teenager. This was a top of the line Aerostar and had a readout for miles per gallon. My son consistently posted the highest gasoline mileage of anyone in our house. I finally took a trip and let him do the driving to observe how he got the high mileage. I found he had a vision problem–we went the entire 200 miles and he didn’t spot a single other motorist of illegitimate birth. I average three such motorists per mile. The point is that my son is a non-aggressive laid back person that is reflected in his driving habits, while I tend to be more aggressive. This makes a difference in gasoline mileage.

If you want highway MPG, you have to drive on a long trip until you need fuel. Have you gone on a 300 mile trip? Miles divided by gallons will give you your miles per gallon. If you have a loaded vehicle, the MPG will be less than the rating “for your class of vehicle”.

I have the 4.8 litre engine with four speed automatic and roll up windows with manual door locks, front AC only. 4WD. Your fuel economy seems bad. My truck gets 12.5 MPG when driving locally and 18.5 on the highway. I take a long trip once every 16 months. It is a 2002 GMC Sierra, 1500 extended cab. Tires are P245 75 R 16.

And, the rest of the story. Thanks to a visit to the dealer and a drive with the mechanic, we have an answer. With the intention of being green, the truck was driven too slowly. An indicator of the driving speed (which in hind sight was a key to the mileage problem) was too-frequent shifting. Once the speed was increased, the mileage came down to an acceptable level.

p.s. Thanks for all the tips on calculating MPG. With 40+ years of driving and doing calculations…that was a skill that was well in hand.