Hi all !!! I'm new here and I'm from north of Montreal (Quebec), I'm french and I'll try to write the best I can.

Here is my trouble.
I bought the truck on november 2009 and I only got 10 to 14 mpg.
I did: Spark plugs (Ac Delco Iridium), Air filter,Throttle body cleaned,Tire pressure OK, O2 Sensors looks ok but not sure (Scantool), I drive smooth,I seafoamed (except oil), Transmission fluid flush (dexron 3), Transfercase fluid changed (GM fluid) and differential fluid changed.
MPG are hand calculated each time I fill up.

What next.... People claim they get as mush as 18 and more MPG.

H E L P !!!

Thank you all for your future help.

MAF sensor cleaning & PCV replacement

Correct me if I'm wrong but I dont have MAF and PCV on my Trailblazer 4.2L I6 2003.

Just discovered the fuel economy threads so maybe someone could move this thread to the right place please or it's ok here .

Thank you.

My dad has a 08 trailblazer and averages 12-13 mpg He only has like 6,000 miles on it to, and he granny drives it! Its weird how the mileage is so terrible with it...

my bro has an early 2000s trailer blazer with the I-6 and it gets worse gas mileage then my 5.3...i too have been scratching my head trying to figure out why they are so thirsty..is the frame made of lead?

Welcome !


I'm no expert here.

Some has to do with resistance - like tires.

Temperature affects MPG. Gear ratio.

Lead foot.

I have read by others who claim great gas mileage. I think they live in warm climates with flat roads. Or mathematics was not one of their better subjects in high school.

I do like cars I've seen that provide the gas mileage right on the dash.

Who else has a TB in here? Maybe we can get some folks to chime in and tell us what kind of mileage they get. I don't know what is normal here.

12 city, 16-18 highway..for 4x4 I6....sad i know

I have the same thing, 4x4 I6 TB LTZ and I get about the same exact milage.

02' TB I6 LTZ also, same mileage...

theres not much else you can do man to get more mpgs, maybe a tune..or just get a clydesdale to pull it..

2002 Bravada AWD, pretty much 15 MPG all the time.

Yes, and people also exaggerate and lie about their mileage. These vehicles do not get good fuel economy by design alone.

its not a lie if they are pushing or pulling it to save gas

I used to have a 2004 TB I-6 4x4 and averaged about 17-18mpg. I was satisfied with the MPG, relative to how it pulled when passing, and off the line. TBs are not little trucks, like the old blazers were.

Hmm, my mom's 2002 Envoy I6 usually gets 15 mpg city and ~21 mpg highway (65-70 mph) Those numbers are by DIC but typically check out pretty close to the hand calcs.

2007 LS V6 4x4 32,000 miles
13-14 city 18-19 highway

thats odd.
i have a 2005 trailblazer with the 4.2 I6 and i get 18 in town and 21 highway
its not to horrible at least......
thinking of it maybe i should hand calc it to be sure.

if your going off the DIC its probably off

yea i am. im guna fill up today and see what i get from there

There's a reason i bought a Blazer over a Trailblazer. Smaller, better MPG (my lowest was 12 and i was missing on two cylinders, usually i get 18-22), and just as much power, without sacrificing 4WD.

Would you mind sharing that link??