mpg with h3 07 with 87oct/33lbs air in 33 inch tires, highway speed, is 18 mpg, interstate is 16 mpg 70 mpg. is this average or am i just lucky??
i also plan some updates to the exhaust and intake and computer, i would like to get 20mpg highway,

 

Thats just a bit lower than I get, but then I have a standard. I have considered the above additions myself, but can not rationalize the cost in respect tofuel savings. @ 2 miles per gallon average increase, you would need to purchase 40 gallons to offsetthe price by 1 gallon of fuel. Therefore, the difference @ 100,000 miles would be 555.6 gallons or $1666.80 @ $3.00/gallon. So, if you would actually be able to squeeze an extra 4 MPG's out you'd not realize a savings for longer than most people own their vehicles.

Now, if you were simply looking for a "seat of the pants" increase by modification, go for it!!

 

thanks for the cost estimation. Im do so enjoy this site, its very positive to see how every one is so helpfull, In taking you estimate in concideration. do you think the performance increase would be worth the expense?? cost estimate of 500 for exhaust. 150 for doc,s intake, and 69$ slr chip,,..?

 

Well, the hummer is about as aerodynamic as a brick. Making the vehicle your own by adding bolt-on performance or parts for the purpose of individuality is completely for the owner's personal enjoyment. As long as you understand the cost will in most cases be unrecoverable (unless you sell to someone who has the exact same taste), bolt till your hearts content.

 

Worth It!
I get 23 mpg at 65-70 mph and 20 mpg70-75 mph. Goes down hill from there. I avg. 18.5city/hwy per tank around my home town.I do have a volant exhaust, volant air intake, helix power tower tbs, and a custom ram-air intake to the air box. It will be awhile before I make my money back,but i enjoy the look on peoples face when I tell them I drive a hummer and get over 20 mpg. Thesemi-environmentally friendly H3. Has a ring. Might even get a bumpersticker made thatsays.

"A Hummer that gets over 20 mpg, the world must be coming to an end."

later guys!

 

Just curious, what did all of that set you back??

 

Thanks, I am glad to hear of your mpg , please send me the part numbers and cost if you can, I have a friend who is currantly working with developing a heated gas line to preheat the gas before it hits the combustion chamber, he states that he is hoping to increase his mpg, he is working with re routing the gas through the radiator in such a way as to heat the fuel, alot of his work he wont tell me the specifics about because of patient,s he is trying to obtain. He is basing his figures on gas expantion at a ration of 3 to 1.

 

Something is wrong with this picture!! I've done the PCM4less, B&B exhaust, K&N CAI and intake resonator by pass and the best mileage I get at 65mph is 18! I have troubles believing the over 20mpg

 

I also do not belieive people are getting over 20 mpg

I have 06 h3 edventure with 33's. gibson exhaust , K and N intake, and a pcm retune

65,000 and I average 17.5 mpg overall. but even on long road trips downt the highway I have never got 20

 

That's my point! I even pump my tires up to 35 lbs to reduce my rolling friction. 18mpg is my best. And I drive like I had a raw egg under my foot.