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  1. #1

    Default Poor Gas mileage

    I specifically signed up on this website to voice my disappointment on my gas mileage. I bought a 2004 Trailblazer EXT in May 2004 and I'm getting @11 to 12 mpg in City driving and @ 14-15 mpg on the Highway in California. I've took the Trailblazer back to the Dealer where I bought it, and they did not find anything wrong with it. I've tried different brands of gas, even added a Tornado, but still lousy gas mileage. If anybody out there can recommend something let me know.

  2. #2

    Default RE: Poor Gas mileage

    That's pretty low on both extremes. Do you punch it off the line? I spent some time in Southern California and I know that speed and acceleration are a taught in drivers ed.

    Seriously though, you're at least 25% lower than you probably should be. Driving style is often the culprit, but maybe you've got a fuel leak, or could be a number of things. I wonder what the average of the board is. Anyone else get this type of mileage.

    10 Chevy Traverse LT AWD
    02 Chevy Trailblazer LS (110K+ miles - loaded except for 4WD - WRECKED!)
    99 Chevy Cavalier LS (105K+ miles - commuter car)
    78 Chevy Suburban Silverado (454, 3/4 ton)
    62 GMC 3/4 ton Pickup (350 police interceptor)

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  3. #3

    Default Poor Gas mileage

    When I searched online for "poor gas mileage for 2002 Chevy Trailblazer, your site came up. I just purchased a 2002 Trailblazer LT with 50,000 miles on it and am getting only 12 miles city driving and 14-15 highway. I live in Central NY and am very disappointed. I used some STP gas treatment and fuel injection additive, but it looks like that didn't do anything either. Any thoughts - the car is still under the used dealer's warranty for another month or so. Thanks.

  4. #4

    Default Poor gas mileage

    Well, that's two in a row that have problems with the gas mileage. I have found that I get 18.4 on average.

    There was a recent news story about how gas mileage can fluctuate greatly, and how the EPA is going to recommend changing how car manufacturers test their cars. I'll see if I can't find a link to it.

  5. #5

    Default Trailblazer poor gas mileage

    I love the way its rides. Its real smooth. But the gas!!! I have a cousin who is a mechanic and he Scoped the Trailblazer and found nothing wrong either. He checked it before I took it into the Dealer. The one big thing he found was that the EXT curb weight is 6200 lbs. That's more than an Astro Van or a single cab pickup. After getting it back from the Dealer, its mpg was very efficient. But as soon after the gas ran out and I refilled it, back to the same old bad mpg. I wonder if the Dealer added some type of additive to the gas.

  6. #6


    wow, holy bringing thread back from the dead...

    I get just about 17-17.5 in my '03 bravada w/94k and awd... I don't really like having the rig shift above 2k rpms..I really notice the fuel savings if the conditions are right...flat road, about 40-50mph, and rpms are at just about 1200..

    I actually got 24mpg (city) once, at least according to the instant eco mpg calculator. What is everyone else getting now? (3years later)
    Vinnie - New Hampshire
    2003 Oldsmobile Bravada - loaded to the gills and awd - 94k

  7. #7


    I actually spent quite a bit of time looking at MPG improvements in the last year or so. The biggest factors are clearly from the driver. All vehicles get horrible mileage in stop and go traffic. Even a Prius will be 15 MPG or worse in the heaviest of stop and go traffic, so a Trailblazer EXT would be like 11-12 for the most part.

    Once you get open, a lot of people punch it hard and go 90 to try to catch up on time, well that sucks down gas too, each MPG over about 55 starts to affect the mileage pretty hard.

    My folks are driving a 38' Bounder motorhome, they slowed down to 60 on their last trip out here and saw an increase of 20% on their mileage over going 70 to 75.

  8. #8
    Sr. Engineer
    TomsHHR's Avatar
    Join Date
    Feb 2007
    Superior Wis
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    Ok, I will not mention again my HHR gets from 27.5 to 34 mpg.

    2009 Chevy Sliverado Std cab 5.3, 4 speed Auto 2wd, Trifecta Tuned
    1926 Model T Bucket powered by Chevy LS 5.3 TH350 and S-10 rear axle Build period Sept 7, 2010 to April 2011
    1979 Starcraft Islander 221 Great Lakes Fishing Boat
    SOLD: 2006 Chevy HHR The Deer Slayer.

  9. #9

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


    Art-the 6200 lbs is the maximum allowed weight of a fully loaded Trailblazer. This means It weighs about 4600 lbs without any cargo or passengers in it.I can never keep all the "weights" straight.
    Curb weight is what it actually weighs coming from the factory with all fluids.
    Another weight is the maximum loaded weight(counting tongue weight if towing)..-the 6200 lbs
    A third weight is the maximum it can weigh and tow-Probably about 12000 lbs for your vehicle.

    Still 10-12 mpg city and 15 hy is waaay down.

    Do you have ethanol in the gas there? 10% ethanol is supposed to drop the MPG just 3% , but many folks find it hits at least 5% and some say 10%. 5-10% is about 1 mpg. Try some no ethanol gas.

    Many folks with 2wd 6 cylinder Trailblazers get 25 mpg in pure highway driving at 65 mph on level roads. Are you folks in hills - driving in hilly areas really hurts mpg.

    Driving very cautiously in the city I get 11-16 mpg with my 1998 Suburban.In pure highway-level interstates- it gets 21 mpg at 68 mph with the cruise control on. Your Trailblazer is about 20%better than the older Suburbans, so you should get 15 city and 22-24 hy driving carefully..


    Last edited by phoebeisis; 08-10-2008 at 01:41 PM.
    1998 suburban-
    1/2 ton

    199500 miles

  10. #10

    Default Poor gas mileage

    You might try looking at

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