importkiller. I am a new H3 owner and I am also having problems with my gas mileage. I consistently get 11 to 12.5 miles per gallon. I am a conservative driver on the road (80% city 20% highway).

The dealer says that there is nothing they can do. They have also told me that the engine needs to break in. I have a few thousand miles already... how long is it supposed to take?

Anyway. Have you made any headway with your problem? I'm sure we would both be happy if we could at least get 14 or 15 MPG.

I have a base model, auto trans, with the 265 tires.

 

I've only checked my mpg once so far (I guess it is out of denial LOL), I got 13.8mpg on one of my first fill fill ups, but then again I did try to see how fast I could take the hummer up to on the highway on that tank of gas... got to 95-96mph before the thoughts of me not knowing the speed rating of my tires kicked in. The truck was still pulling though... milage should increase after the engine is broken in.

I don't know if our H3 computer program is the same as my friend's 05 GTO or not, but the first start up after 5000 miles the GTO computer changes the tune from a 'break-in' tune to a more aggressive tune (maybe 5-10rwhp, nothing extreme). I think he might be getting a little better gas milage now, but I doubt it makes a difference for him, he has a lead foot to say the least... [sm=gears.gif]

 

I would be okay with getting 13.8 MPG. I sure hope the mileage improves. If I am only going to get 11 to 12.5 MPG then I sould have gotten an H2!

 

I haven't contacted the dealership yet, no time to bring it in until things settle down around here a bit. I don't have 5000 on the clock yet but my mileage is getting worse, not better. My first tank brought me 12.5 my last tank was 10.7. One thing I did do this weekend was went out to big empty parking lot and put it in 4 lock made a few turns so I could feel the 4 wheel front end lurch then switched back into normal full time 4 wheel mode. The front end lurch went away but not completely, so I put it into reverse and did a few 5-10 mph backup donuts. Did 2-3 going left then another 2 going right. After the first one going right (in reverse) I felt the front end kinda pop (hard to describe). I then went forward and there is absolutely no front end lurch at all. I put it back into 4 lock to make sure everything was ok and it is, then back into full time 4 and this time it kicked right into normal full time 4 wheel drive with no front end lurch. I'm guessing something didn't fully dissengage the first time. Won't know if this was the cause for my mileage woes but will in a few days.

 

Thanks. I will make sure that I am in normal full time all wheel drive.

 

You should be getting at least 20mpg! I guess your rig didn't see those "magic commercials"!

 

That's for sure. Mine has almost 18k miles on it and it's getting good mileage.

I also notice I get better mileage with higher octane gas. Everybody says that the 92/93 octane doesnt do anything, but it sure does for ours. If you do the math, at least for mine, it ends up being about the same price for gas since we get better mileage for higher octane, and I do like the fact that supposedly I'm getting cleaner gas and better mileage and don't have to fill up as much. If I can save a day or two on going to the gas station I will. I started switching back and forth recently, not back to back, and definitely notice that the engine is smoother with 93 octane and a little better mileage. Still, you guys shouldn't be getting that bad of mileage, ESPECIALLY after those new commercials. You could sue them for false advertising, or misleading the consumer. We could even get a class-action lawsuit giong I would never do something like that though.

 

These mpg numbers are somewhat shocking to me. My oddometer just turned 21,000 miles. I usually get 330 to 340 miles per 20 gallons of gas. I have averaged 16 to 17 mpg since I bought my H3 over a year ago. That is primarily city driving. I got 23 miles per gallon when I drove from Pittsburgh to Niagra Falls. I only use 87 octane gas. I have noticed some improvement now that I use Mobil 1 motor oil.

 

I'm with you, but obviously importkiller has a problem if he's getting mileage that bad.

ImportKiller: You aren't using that high-elevation 85 octane stuff they sell in the mountains are you? I noticed when I went on a road trip last year that they sell lower octane in different parts of the country. Hell I didn't know

We are ALL going to go to the dealer with ImportKiller and say "If you don't fix our friends H3 we are going to fix you buddy!"

 

I use regular Sunoco 87 I believe. I burn fuel till low fuel comes on and everytime I fill up at that point with 20 gallons. The most I have ever gotten was around 240 miles per tank. Once I install the 35's I should go down to around 6 mpg......still better than my dually