Is this normal gas mileage?

[Loco-diablo]

Now all highway I've gotten 29mpg thought that was really good.

29 is outstanding! That must be a one off occasion, or traveling mostly flat land. I can't imagine 29 mpg being the average highway mpg with the 5.3.

 

The best mpg I managed to get with my 2017 5.3 DC was on a 130 mile trip from central Massachusetts to Cape Cod. While babying the gas pedal and keeping to the 65 mph speed limit the whole way, I managed to get 25.2 mpg. I was amazed!

29 is outstanding! But definitely not the norm.

 

My all around average (80% highway, 20% city)has been about 19.5 mpg during my 5000 miles of ownership. I'm definitely happy with that. It's about the same as I was getting with my 2008 V6 Tacoma.

 

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[CounterMeasure]

Took a 90 mile round trip yesterday, never going above 70mph. My 6.2L made 22.1mpg.

 

Once my new truck is here, I am going miss what that engine can do in my truck, but won't miss much else on/in the truck around it.

[Motor City Rick]

From the U.S. Department of Energy 2014 Sierra V6 gas mileage stats are this:

 

Website: http://www.fueleconomy.gov/feg/bymodel/2014_GMC_Sierra.shtml

 

2WD = 18 City, 23 Highway, 20 combined

 

4WD = 17 City, 22 Highway, 19 combined

 

Note: Highway gas mileage test speeds are tested around 60 to 65 mph, not 70 to 80 mph, as most trucks do, hence lesser highway gas mileage by 10% minimum.

 

When using 10% ethanol based fuels (which 95% of the driving public uses), drops another 7 to 10% in fuel mileage. Using E-85, drops 30% in mileage from gasoline.

 

There is a lot of "other" factors not mentioned.

 

The type of engine oil used, synthetic or organic, what weight oil is used? Referring to the internal friction coefficient of motor operation.

 

How much is the motor running over 3,000 rpm's?

 

How many stop lights / idle time?

 

Hot climate / better mileage / cold climate / much lower mileage.

 

High altitude, lower mileage / low altitude, higher mileage.

 

Is the person a "lead foot"???

 

Is the truck jacked up to the clouds running 36 inchers?

 

Does the person have box cap or open box?

 

Does the person have west coast mirrors, mud flaps and running boards or light bar on the roof???

 

Is the there a 8 inch lift kit involved? Any lift kit reduces gas mileage and vehicle power.

 

Is cruise control used quickly / frequently when going into highway mode?

 

Is there any unnecessary weight added?

 

Large diameter wheels are good for highway, small diameter wheels for city / stop 'n go driving. All depends on overall gearing efficiency for the use at hand.

 

The biggie, what axle ratio is used for the type of driving??? Low ratio's if mostly highway driving like 3.08

 

High ratio is for pulling trailers / towing something heavy like 3.73 axle

 

Good city / highway axles are 3.23, 3.42, depending the use and type of driving.

 

When I did gas mileage diagnosis, it was either wrong axle ratio usage, too much heavy throttle / top speed issues, cheap fuel issues, all the exterior extend body modifications like mud flaps, running boards, west coast mirrors, light bars and the biggie was ridiculous tire size / tread design from aftermarket modified wheel / tires when the vehicle was still under warranty.

 

If people knew the 5 coefficients of drag, gas mileage can be improved greatly.

[ewiski]

Sorry but i dont believe anyone gets 29mpg in these trucks as an average. maybe going down hill. Or doing 50 on the freeway. but i still doubt it. I drive a toyota camry also and my average mpg is barely 25 for mostly city driving.

[Motor City Rick]

It's gotta be a miscalculation on fuel mileage, or a typo!!!

 

I have a much smaller / lighter 4 popper Sonoma that has been lowered to the height of a car (58 inches), GU4 highway axle (3.08) geared to 1950 rpm's @70 mph, Engine fan has been change over to full electric twin fans. Cold air induction system. Reprogrammed ECM, ZQ8 wheels / street tires with cruise on.

 

Getting 25 miles to the gallon on the highway is a chore. Helps with a 40 mile an hour tailwind following a semi.

[Z71_Tommy]

I pulled that going from parowan Utah going back to las vegas Nevada. I was just outside of the gorge heading into mesquite when I pulled that 29mpg cruise set at 75mph and just cruised away. I was very impressed. Only modifications done on truck are magnaflow cat back with a race muffler 6x6x12 canister 3" in and 3" out. An a drop in K&N filter.

 

29 is outstanding! That must be a one off occasion, or traveling mostly flat land. I can't imagine 29 mpg being the average highway mpg with the 5.3.

The best mpg I managed to get with my 2017 5.3 DC was on a 130 mile trip from central Massachusetts to Cape Cod. While babying the gas pedal and keeping to the 65 mph speed limit the whole way, I managed to get 25.2 mpg. I was amazed!

29 is outstanding! But definitely not the norm.

My all around average (80% highway, 20% city)has been about 19.5 mpg during my 5000 miles of ownership. I'm definitely happy with that. It's about the same as I was getting with my 2008 V6 Tacoma.

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[Nanotech Environmental]

I pulled that going from parowan Utah going back to las vegas Nevada. I was just outside of the gorge heading into mesquite when I pulled that 29mpg cruise set at 75mph and just cruised away. I was very impressed. Only modifications done on truck are magnaflow cat back with a race muffler 6x6x12 canister 3" in and 3" out. An a drop in K&N filter.

 

So, what you're saying is that is was only for a short section on that trip?

[Z71_Tommy]

So, what you're saying is that is was only for a short section on that trip?

About 40 miles or so. Then got into some grades.

 

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[Z71_Tommy]

Sorry but i dont believe anyone gets 29mpg in these trucks as an average. maybe going down hill. Or doing 50 on the freeway. but i still doubt it. I drive a toyota camry also and my average mpg is barely 25 for mostly city driving.

I was coming back to Vegas Nevada from Parowan Utah. I should say best was 29 mpg pulled that for about 40 miles or so. Average of that trip was 24-25 mpg. 75 mph cruise set. Dropped to V4 and mpg just climed.

 

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[Gofas]

Sorry but i dont believe anyone gets 29mpg in these trucks as an average. maybe going down hill. Or doing 50 on the freeway. but i still doubt it. I drive a toyota camry also and my average mpg is barely 25 for mostly city driving.

I got a 26.7 for 50 miles from sierras to death valley last year. Just recently lost 1 mpg with all terrains at 265/65/18.

[J0E]

14 V6 2wd double cab, leveled, stock 20s, stock size all terrains.

 

In the 3500 miles I've had my truck I've averaged a hair over 20mpg. Hand calculated tanks are between 19-22. I'd say I drive pretty close to 50-50 highway/city.

 

Although my "city" is 55 mph back roads with a small town in the middle.

 

 

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[SNOWMAN CUSTOM BAITS]

2015 5.3 3.42 crew cab 4wd 285/70/17 mud tires 2.5 RC level I get 11 to 12 mpg in town. I have gotten 19 on interstate driving 70-75. On small highway driving 55 I have gotten 24.

[Mark Diedrich]

14 V6 2wd double cab, leveled, stock 20s, stock size all terrains.

 

In the 3500 miles I've had my truck I've averaged a hair over 20mpg. Hand calculated tanks are between 19-22. I'd say I drive pretty close to 50-50 highway/city.

 

Although my "city" is 55 mph back roads with a small town in the middle.

 

 

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[Mark Diedrich]

Lol, that's not even close to city driving!.....55mph backwoods and your going through a small rural town..... That's closer to highway driving, with limited slow downs at each destination.

[Lgetz]

City driving I get between 12.0-13.7 mpg with current level/tire setup. Before on stockers about 13.5-14.7 all according to the DIC. Lifetime average over 24,001 miles at 16.2 mpg. Went down from 17.6mpg over 4000+ miles compared to mileage on stock tires.