everyone that has had head/valve issues

Did you notice poor gas mileage before you had the repair done? as you all know the best mileage I ever got 12 mpg and for the past month or so I am down to below 9 mpg. I just found out today that I have an engine misfire code from 280 miles ago, from reading all your posts it seems that almost all of you got the same code also. Just wondering if this could be the reason I have always got bad gas mileage.

Now we've got 3 "head/Valve" threads I have to keep up with? GRRRRRR Killer, I was on a trip when I had my prob happen - therefore I was checking gas mi. closely. I averaged approx 15-16 mpg the whole trip until I could get home to the dealership. 9-12 MPG OMG!!?? Uh could it be the way you drive? <just askin> If not..WOW how bad for you...might as well be gassin up that big ole #2 hog! (One big reason I chose to go 3..didnt want to go broke in gas alone!)

I thought it was my style of driving because I hate getting passed But when I was in the hospital a few weeks ago my wife was the only driver of the truck and she got 9.5 mpg for the entire week, so it can't be me. BTW...my wife drives like an old lady....well you know...like a woman J/K!!

Yeah, so does the hubby when he gets in it...so I don't let him drive it much![

Below - find my mileage - do understand i fish on the beach, so mpg may be down due to the 4x4 factor... this is PRE-VALVE issue...

Just got H3 back POST-VALVE issue - so look out for the new miles...

257.6 miles 15 gallons
17.17 mpg 091106

213.9 miles 14 gallons
15.02 mpg 091806

188.4 miles 12.2 gallons
15.4 mpg 092406

162.4 miles 9.6 gallons
16.6 mpg 092106

186.8 miles 12 gallons
15.5 mpg 092306

227.5 miles 14.8 gallons
15.7 mpg 092606

13 gallons 202.9 miles
15.6 mpg

12.4 gallons 193.3 miles 100306
15.5 mpg

239.3 miles 15 gallons 100706
15.9 mpg

223.5 miles 14 gallons 100806
15.9 mpg

251.3 miles 101906 15 gallons
16.7 mpg

204.4 miles 102606 13.6gallons
15.0 mpg

234.9 miles 103006 15 gallons
15.6 mpg

wow..those numbers are alot better than mine ever were

Yeah, I am pretty psyched...

It is the 06' Adv and Lux package Automatic (kind of wish I had the stick)...

Was getting 13-14 with my LR

My mileage was slightly lower than average when my light came on. My lowest mileage was a few tanks before that, and I think that was probably still breaking in.

-Alan

I am actually hoping my heads go and soon...my mileage is terrible and getting worse and no dealer seems to be able to anything about it. they all just say...due to larger tires. I asked the last one if they could check the pcm and see if there is something out of whack or maybe flash it and i was told there is no flash available and that they couldn't do anyhting with 35" tires on it. I called three other dealers and they all gave me the same crap. I just filled up again tonight, went 187 on a full tank, filled up with 20.4 gallons---9.16 mpg...impressive.

What you might want to try, to prove your tires aren't the prime culprit in your mileage is to go out and get some cheap 33's to put on, run a couple of tanks through while keeping serious trak of your pre and post tire change fuel economy, then go in and say WTF with the 33's on.

Also, I was thinking, aren't you the one who only puts $20 in at a time, and only when the tank is empty? If so, try actually going from full to something less than full, then fill back up and not the mileage traveled. This will be more acurate then guestimating. If not, sorry for the confusion.

yea I normally only put $20 in at a time once the light comes on but I always fill it and test mileage twice a month or after a mod or repair is done. I do keep a log of mileage and I never got over 12.5 with the base tires (265's I think). My normal mileage was always around 10-11 mpg with the 265's. With the 35's it went down to 9-10 then I installed the k&n fipk and my mileage with 35's went up to close to 11. I got the check engine light a few weeks ago ( I posted about it when I got the light) ever since then my mileage has been back in the 9's. I just hope that if the motor does go it doesn't happen when my wife and son are in the truck.

Most of my driving quite the same, yet different, if that makes sense....

If I am not driving highway, then I am running it on the beach, 4x4 top speed at about 15MPH.

The fishing season is a bit done here in RI, so i will be able to get a true account over the next few weeks and will post.

You have the misfire code and they won't check the heads and valves? That doesn't seem right.

In my case, I told the dealer the idle seemed odd and he said he couldn't do anything without a code. 100 miles later I had the code, took it back, and they immediately checked the valves.

Maybe tires can affect mileage? But they ought to at least check you engine.

-Alan

Importkiller, there is something seriously wrong with your H3. I have nearly 26,000 miles on mine and get an average of 330 miles per tank full. This averages out to about 16.5 mpg. This is all in city driving. The best I ever got was 450 miles driving the PA turnpike. That is over 22 mpg. I would be bitching at the dealer big time for such ****ty numbers.

I'll just wait for the motor to die then push it in front of a freight train.... I'll get an 07 with the insurance money

Post head job.....drove her nearly 300 miles today and still 1/4 tank of gas left (average speeds of 80+)...drove like a dream, in fact had to rein it in a bit several times as she was raring to go! I am thinking the mpg will be about the same as it was pre head job...approx 15-16 mpg.

300 miles to 3/4 tank....good lord..I'm jealous

I got less than 200 miles on my last tank when the low fuel light came on

WOW, speakin of "Bummers" Yours really is.... KA-CHING!! KA-CHING!! I feeeeeeeeeeeeel for you! I'd be sittin on their doorstep with that thing because something really is wrong with it unless there are other underlying reasons such as aftermarket/add ons, tires, etc., or driving habits.....

I am no expert, not by any stretch. but i do know if you go up more than 2 sizes in tire size it is strongly recomended that you step up to shorter gears ( larger numarically ex. 4.11 is shorter than 3.73.) that might be the corp of your problem. the engine and tranny are having to work overtime to move the tires. more wear especally on the tranny. GM really should have put a bigger engine in the H3 in i personally think it is under powered. I drove one and was less than impressed with the power. Not trying to start any fights mind you. another thing to think about and you might already know this, but taller tires roll further, and there for your speedometer will read slow. so you will actually be travling faster than you think, and that might factor into the mileage. hope this helps.

there are alot of guys that I know running 35's on their h3's with stock gearing and still getting up around 14mpg+ so I doubt too high of a gear is my problem. And my mileage numbers and speed numbers are taken off my gps, not the speedo/odo...GPS doesn't care what size tires you have, it's always accurate.

I do not have documentation in front of me at the moment but doesn't the H3 have a 4.56 ratio rear end??? How much shorter can you go???
 
As for short on power When it can pull a dead half ton Chevy pick up 150 feet across a parking lot with 31 inches of snow in it...I see NO LACK OF POWER! Kick ass balls to the wall with plenty to spare.

quote:

ORIGINAL: importkiller

there are alot of guys that I know running 35's on their h3's with stock gearing and still getting up around 14mpg+ so I doubt too high of a gear is my problem. And my mileage numbers and speed numbers are taken off my gps, not the speedo/odo...GPS doesn't care what size tires you have, it's always accurate.

I'm running 35's, marker lights, SMA brushguard and rockrails. I get 12.5 mpg mostly city driving. My truck is in the shop right now, got the engine misfire code last week.

Shell..don't forget to post a vote on the poll below..we are tracking the numbers..

quote:

ORIGINAL: Dennis

Shell..don't forget to post a vote on the poll below..we are tracking the numbers..

Where is the poll? can't find it.

Two threads below this one..
 
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