I'm driving a month old stock '08 H3 with <1,000 miles on the clock and am getting 18.5 around town - about 25-30 mph average. I can only assume I'll do a bit better on the highway and as the car ages. I don't see 20+ as unrealistic at all.

 

Sorry people, but I just don't get it!! A duck, is a duck, is a duck!! I don't think any of us bought these vehicles expecting stellar fuel economy, & the boltingon of partsto gain a mile or two per gallon will never offer a financial return on that investment in respect to either fuel economy or resale value!! You would be much better off buying gold & playing the commodity marketsto offset the cost of fuel. Trust me, that works

 

Hey guys, I agree with all of your statements, But I do think some of the H3s get better gas milage, it may be altitude, tempature, driving habits it all has an effect, but I plan to spend about 700 bucks on a exhaust system and a air intake from Z-DOC lol and a k&N filter, I will post my results, also using lucas oil fuel additivetokeep fuel injectors clean is very important, I also think the use of synthetic oil makes a small difference, and when u combine all of these things together it can add u, Besides i like the look on peoples face when i tell them i get 20 mpg

 

Indeed! I suspect that if such numbers could be consistently achieved with relatively simple bolt-on accessories, GM would have done it a long time ago and wouldn't be in the shape that it's in today with Hummer. That said, the nature of mass production is such that varying mileage figures on different units is completely expected. Drivers' technique is another big variable. As I said, the numbers I'm getting today suggest that 20+ is not out of the question. However, I doubt that add on devices would give improvements that would have any kind of practical payback.

 

Hey guys!
Sorry it took me awhile to get back. The stretch of road I drive is very flat and I am meticulous withthe pedal it is sort of a personal goal to reach 20 mpg. when I drive. I did mention a cusom air scoop is it possible that that would help that much? I checked my math and the miles to gallon ratio at fill up is 18.5 mpg average with mixed driving and over 20 hwy if I go 65 or less.

exhaust - $ 450 ebay
intake - $ 160 autoanything
TBS - $100 autoanything

 

Ok how do I post pictures?

 

I have a stock 07 H3 and I drive it back and forth between Tucson AZ and Flagstaff AZ (desert and mountains). If I drive at 65 mph I get 20/21 mpg. When I drive 80 mph I only get 16 mpg!! The only thing different is I use Mobile 1 oil and Imake sure my air cleaner stays clean!! I think driving habits make a big difference.

 

Im in flat Ohio. I use mobil one and an improves exhaust and PCM. I drive 65mph and never have seen anything near 20 mpg. But I guess I could lie?[sm=laughat.gif]

 

D.Vader, I guess your foot must be a LOT heavier than mine !!!!!!!

 

Indeed! Though, other than judicious use of the clutch and an 'egg under the foot' approach to the accelerator pedal, I don't know what I do that is dramatically different than 'everybody else'. I've generally been pleased with how my numbers have met, and frequently exceeded the EPA numbers over the years. The EPA gives the H3 13/18 (I think). I've been getting about 18/20 in the 1.5 months since I bought it - still too soon to call, but I'm certainly not complaining. A few cars prior to that were close enough to the EPA numbers to keep me happy. The doozie, though, was my old '87 Chevy Caprice with a 305ci carbureted engine. Over the 150K miles that I drove it, that car *consistently* gave me 14/30. I originally assumed my math was wrong, but I confirmed it on subsequent trips. IIRC, the more optimistic EPA of those days gave it something like 12/15. I chalked that one up to a 'mistake' on the production line (they accidentally installed an 'experimental' carburetor on my car - you know, the one that the oil companies paid GM big bucks to squelch. We've all heard that story.) Though I rebuilt the carb at 100K miles (remember Jiffy Kit?) and got the same results.