How to improve H2 gas mileage?
 

There’s a way by Tuning the enigine professionally to get maybe 2 miles on the gallon more.
IMO, you don’t get a hummer for the gas mileage, you get one cause you love the hummer style of driving, the icon and the overall look as many hummer owners personalize their vehicle.
As my everyday drive I have a 2015 Chevy HD 2500 Diesel, deleted a bunch of stuff out of it, deleted the whole DEF system and with that the converter and replaced it with a straight pipe.
Installed a performance kit and I get on the freeway with speeds 70 to 80 miles an average of 27.4 miles on the gallon, in the city about 16 and yes I got all terrain tires on it as well.
My 2008 H2 I’m lucky I get 10 miles on the freeway but in Texas the fuel prices ain’t to bad.
Filled her up yesterday for $2.39 on the gallon.

Synthetic fluids, new spark plugs, wires and 02 sensors, remove the spare tire and roof racks, tires with a more street tread ran at maximum inflation, drive like an old man.

Yes, you are absolutely right. When I bought it, it was because of its appearance and personality. But I believe anyone would want to improve their car to get better performance and fuel economy. Fuel economy is the only reason that discourages everyone from buying it. I still hope that more people can provide more modification plans and product brands.

Do the math on conversions, adds, modifications etc.... Now, take the number of what you have gained for MPG & figure out how many gallons of gas it would take to have saved to pay for these modifications...... Its right up there with solar panels on your house (I have 40)- if you live to 100 you may see a savings in cost vs savings realized....
Just drive it & dont worry about it. Make more sense to buy another vehicle & park the H2 vs trying to save with the H2......

You seem to have missed the point of my question. I’m not asking how to save money with the H2, I’m asking how to improve its fuel economy. I know it’s not a fuel-efficient vehicle, but I love its style and character. I’m looking for some tips and suggestions on how to upgrade the H2 to make it more competitive with other vehicles in its class. I don’t need your lectures on math and economics. This is a hummer forum, not an educational institution. If you have nothing helpful to say, please keep it to yourself.

why do you think the world hates the H2... they are gas guzzling pigs.... if they where ment to be efficent they would have came efficent from the factory. the H2 design was offroad capabilities first fuel economy last. it's lineage was the hmmvve that was intended for military use. the military does not care about fuel economy as we tax payers fill there fule tanks.

Maybe this is more the ”Hummer” you should be “driving” fuel efficient and you can burn some tummy also….
https://cimg9.ibsrv.net/gimg/www.hum...1df1226ec.jpeg

The biggest thing I've found is to change your driving style. I get about 9 with my driving style, but I have found that really keeping my foot out of it I was able to get over 14 mpg on my 35 minute drive to school which consists of 50/50 highway and city driving. Just remember that the less input you give to the vehicle both brake and gas, the more mpg you will get, and the h2 is most efficient at around 55-60 mph. Any above that and you quickly begin to drink gas.