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Thread: gas mileage

  1. #1

    Default gas mileage

    have 2011 crew cab z71 2 wheel drive. is there anything to do for better mileage? has 14000 miles

  2. #2

    Red Z71 Max's Avatar
    Join Date
    May 2011
    Myrtle Beach, SC
    Blog Entries


    You could try a high performance cold air intake and a performance exhaust. The addition of these will allow the motor to breath better and should help fuel mileage. There also handheld programmers that have an option for a fuel mileage setting. You will give up some power if that isn't an issue.

    (Scott) Myrtle Beach, SC
    January 2012 ROTM WINNER
    2011 GMC Sierra Z71 MAX 6.2 L w/ Trailering Package
    Rough Country, XD Rockstars, Nitto Trail Grapplers, N Fab, Lund Genesis, Putco, Gator Grip,
    Flowmaster 40 series, Diablosport InTune, Banks Ram Air CAI,
    WeatherTech, AVS Aeroskin, Tow Mirrors,

  3. #3


    In the end any savings you get on fuel from the purchase of those items takes a long time to payoff out of the fuel tank.
    Probably the best way to save fuel is stick close to 60/65 on the highway, be easy on thre thottle no jack rabbit starts, limit idle times.

  4. #4

    Join Date
    Jun 2006
    River Ridge Louisiana-4 miles W of New Orleans-didn't flood-water stopped 800 yards away.


    Gotta agree with TBPLUS- add ons are costly-and usually don't improve part throttle FE in a modern vehicle-certainly not in a drive by wire vehicle.
    Lower HY speeds- use cc on the hy-
    In city driving pulse and glide driving can improve FE by 10-15% pretty easily.
    With GM trucks-modern E- controlled transmissions- when you lift off the throttle completely at 35mph(once warmed up) there will be zero engine braking if you have it in D- just like having it in N.
    Pulse-meaning accelerate normally not slowly- up to 35mph-lift completely off gas-you'll glide up to 37mph-glide down to 28mpg-
    Your average speed will be about 31mph- no problem in a 35mph zone- you'll travel about 1600-1700 feet per cycle-roughly 1/3 mile- you'll use about .14 gallons in this 1700/5280 miles- it will be about 22mpg or a bit better per cycle of 1700 feet.
    If you just hold a steady 35mph-after pulsing up-you will average about 16mpg or so.
    PS Not sure if custom tunes can help FE-got my doubts-OEM engineers are pretty smart- but I don't know for sure on that-
    CAIs- no chance they improve part throttle FE-HP yes full throttle FE maybe a tiny bit- part throttle FE no way??Folks mix up
    volumetric efficiency with fuel economy-improving volumetric efficiency at full throttle doesn't mean better part throttle FE- not with modern vehicles.

    PPS-Should have explained why a CAI won't improve part throttle FE
    If you decrease resistance BEFORE the throttle plate(CAI) your drive by wire will just add resistance by slightly closing the throttle plate-so you end up with EXACTLY the same charge of fuel/air- it it allowed MORE mixture in-you would ACCELERATE-and of course use more fuel.
    On not drive by wire systems-you do the same thing-shut the throttle plate a little-with your right foot.
    Diesels-and older carbed vehicles-might be slightly different story.
    Last edited by phoebeisis; 01-06-2012 at 02:50 PM.
    1998 suburban-
    1/2 ton

    199500 miles

  5. #5
    Sr. Apprentice
    Join Date
    Nov 2011
    Shady Spring, WV


    Before I got the Suburban, the prior owner put a hydrogen kit on the truck. About 400.00 and increase the mileage 3 to 4 mpg. I have not used it, but my brother has it on his Dodge with over 125000 miles and claims 4mpg improvement. I will probably take it off my truck in the spring. I only use it locally so don't worry to much about mileage.

  6. #6


    Over the last 20+ years, I have tried the cold air intakes, the loud exhaust, the hand held programmers, and even the reprogrammed computers. In all cases, it seemed like a waste of money. All of those gimmicks don't help mileage hardly at some cases, I lost 1-2 mpg. If you really look close at the advertisements for the stuff, they say that the real strong power increase (8-10 hp??) comes in at 5500+ rpms. Who the heck drives around at 5000 or more rpms on the street? NOBODY.

    To spend $300 for a cold air intake that does nothing except look cool is really dumb....I am a big Dummy....I admit it. The throttle body spacer is a small boat anchor that does a great job of creating a whistle while you drive....I hate whistles.....another wasted $100. I do like the sound of a nice Magnaflo or Flowmster, and for $300-400 you can have a great sounding car or truck, but it does nothing for MPG.

    Finally in my 60's I have become lee dumb. I realize that the GM engineers are a heck of a lot smarter than I am, and they have done a great job of getting a 4000-6000 pound vehicle (often loaded with stuff) to power down the hiway at 70 mph and still get 15-20 mpg.

    The only thing that really helps improve mpg is the DRIVER. I accelerate slowly from a light, a take my foot off the gas when I see a light change ahead of me, I drive at about the speed limit or a couple of miles over, I do not let the truck idle a lot, and I do buy quality fuel (there is a difference).

    People think I am lying when I say the my 06 AWD 6.0 Liter Escalade gets 19+mpg (cannot get 20....dammmm) highway and 16+ overall....other Escalade owners get a lot less....I am not in a hurry, use a light foot ont he pedal, and save a few bucks at the pump...without buying a bunch of over rated add-ons.
    2011 GMC Sierra HD 2500
    6.0L, Extended Cab, 4x4, 3.73
    2013 Flagstaff "V" Lite, 30', 7300#

  7. #7


    clean the throdle body and intake with some MAP/MAF sensor safe spray.
    clean the air filter intake housing. all of it.
    install K&N air filter (NOT a K&N intake kit)
    sea-foam/carbout the intake
    change fuel filter
    add seafoam/carbout to a full gas tank

    should see an instant improvement of a few MPG, but nothing amazing... its a 5,000 lb truck
    Gas was $1.83 when Obama took office.....

  8. #8


    I changed the fuel filter in my 94 camaro when I bought it. Was getting about 360 miles a tank. Installed a new filter an now I average about 400. So 2 mpg better. Not a big difference, but for 15 bucks, I am happy

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