New owner here. Can anyone tell me the top 10 ways I can save fuel using aftermarket parts? Do the superchips work? Headers? K&N air filter? Any ideas?

 

Driving a 2004 H2 I don't expect much on mileage but tried a lot of things for fun. Here's a list
Volante CAI.........Better response.................................... No increase
Predator with custom tune by Lew at Diablew.... more power......+ 1 mpg.
Tower Power II TBS....feels more responsive????...................No increase
Mobil 1 synthetic 5/30................................................ ......No increase
Granatelli MAF...no difference....went back to stock..............No increase
Electric fans,Tru cool trans cooler,E3 sparkplugs.........................+.6mpg
I found that using cruise as much as possible was more efficient than a light foot. Getting 11.6-11.8 mpg per tank. This I could improve by removing my 3 roof racks, 3rd row seat,and factory air compressor,boom box under rear seat,console vault,coleman cooler,etc.etc. Probably got over 300 lbs of extra weight over stock so I think I'm doing good

 

So far the most notable increase is from the reprogramming of the ecm in our experience. That said it is not a huge difference usually 1-3 mpg... The other stuff also may help, but is usually as mentioned earlier only going to give you better response and power, not really more measurable mpg..

For what it's worth, I have run some different tunes in several of my H2's over the years. So far if you are looking for an off the shelf programmer the Diablo sport has given me the best power & mileage in a hand held on a stock H2.... Hope that helps.. J

 

I would get a snorkel or an airdoc with an aftermarket dry filter, tb spacer, Diablo tuner (the guy above me is getting 16-17mpg with his diablo tuner), aired up tires, and perhaps a more open exhaust. That alone should do some work to mileage/hp.

 

For what it's worth, I don't need full-time 4W-drive. Why didn't Hummer offer a 2wd switch?

 

Because it's a HUMMER, a denoted offroading brand; typically people that buy HUMMERs need 4x4, so awd makes it easier.

Plus the first hummer since the 80's came with full time 4wd. It's heritage.

 

Thanks, your rig looks nice. I'm just looking to save fuel, just ordered a K&N filter, considering headers too. Any other thoughts? Thanks.

 

Appreciate it man!
But seeing as though you have a GM v8, there are LOTS of possibilities of increasing your hp and mpg. Headers, full exhaust, an intake (I would go with a closed system, like the airdoc, to keep the water tight method so true to HUMMER) and a good filter, and a pcm4less or Diablo chip. Those things, according to another guy on here, gets him 16-17mpg highway in his h2; which is pretty damn phenominal.

 

I think I may be that guy you are thinking of that gets that fuel mileage.. But I must keep it in perspective. That is with the premium tune that I installed in my shop. Also that is not pulling anything or putting my foot in it. Also it is using cruise and not speeding excessively (like around 60-70mph) on long stretches of highway.. Otherwise the economy is not that good on the highway. Also the city, back road or towing mileage is lower yet.. J

 

Yep you are who I was thinking of. But basically, you were driving your H2 like a HUMAN BEING and got good mileage :P