87

 

Just what I suspected, the 08' H2's require 92 octane! 03-07'smodels only require87 octane.

 

Bet they don't go out of their way to tell you that.

 

This might be a dumb question but did you reset average mile per gallon after you bought it? I work at a dealership and all of the cars, trucks, and Hummers Average MPG sucks because they are run short distances and idle alot during the winter because they get moved around so they can plow the lot.

 

I thought the 08 was supposed to get better gas mileage than the other models. I was at the dealership this weekend and they told me that Hummer changed a few thing in the motor and that it increased towing capacity. It could be just B*** S*** though.

 

I didn't realize the H2's had such crappy gas mileage. Sheesh.

 

I have an '06 SUT w/25k mi. I get 12.8 in town according to the DIC. If I check actual mileage I'm around 12.0. That is with a light foot and only getting into when needed. Highway I've seen 13-15 depending on conditions and speed.

 

When I originally bought my H2 SUT my mileage was about 10.9 (combo driving) but now after a few small mods my H2 computer average is 13.4, tracking mileage and fuel I have figured my average at 13.3. Not to much difference to quibble about. I can tell you a number of things I did that will help:

1. Remove the cross bars off the roof (easily remove and installed as needed)
2. You can get a little more if you remove the air deflector on the sun roof (don't do this if you like to open the sunroof as you will have a hurricane in your H2). (2 screws and 2 clips, Items 1 and 2 will just about remove all of the air noises at cruise)
3. Add a cover to the rear of your SUT (if you have the factory cover your golden, an expensive tonneau cover will do just fine).
4. Replace the original thermostat with a 160 degree, you engine will run cooler and I believe the computer will give you additional timing advance increasing your mileage. (I used an assembly available for the late model Corvette's, I noticed a slight improvement in performance and slight mileage gain, you will also see a lower transmission temperatures)
5. I removed the rear tire carrier and installed a custom tag bracket for the license tag. (I have the air compressor and repair kit if I get a flat, inexpensive and available at any discount auto parts). The spare carrier is a pain in the *** if you want to drop the tailgate and carry anything, considering I just about live at Home Depot and Lowes this is a great mod. The Carrier is VERY HEAVY and creates additional air drag) You have 2 choices on this, simply remove both the tow hooks (which also holds on the carrier) and place plastic filler caps in the place of the bolts or upgrade your tow loops to stainless, additional expense but it looks great as well as eliminating the spare tire clutter. Clean mean look! The tag bracket I picked up of eBay cheap.


These items add considerable drag and weight to the vehicle and if you don't use them simply remove them. I also clean the air cleaner every oil change (compressed air cleans them up just fine) and use Mobil 1 products in the engine, transmission and x-fer case. These changes cost little but provide good results as well as protect your investment. Overall my H2 is quieter (much less air noise at cruise as well as drive train noise) and is more usable (rear bed) than it was when I bought it. I also love to hear my neighbor complain about the mileage on his Ford Excursion. (If you think your H2 is bad on fuel buy one of these if you really want to see what bad mileage is all about)

Regards,
Dan

 

dude i have to run 93 octane in my 08? how do you know?

 

dude i just read my owners manual it says pretty much to experiment, you can ru 87 but if you beat on it you havr to rum high test, F*CK that sucks $$$$$$$$$$$$$$$$$$$$$$$$