Octane for 2008 H2 with the 6.2 L

[MVR 155]

In my 2008 I only notice a difference using higher octane in the summer months when temps are really high (especially if I am towing). In the cooler months I notice absolutely no difference. The things I notice with the higher octane is increased throttle response along with quicker downshifting and less overall gear hunting.... truck may also seem a tad quicker but that could just be a placebo due to the slightly better response/shifting.

[mikejr]

I noticed my 08 ran like crap on regular fuel. So i always ran premium in it and haven't tried regular in the 09. It felt like it was running of 6 cylinders on regular.

[ben86]

http://www.youtube.com/watch?v=zjZuZjUXU90

i use only 93 v-power.

[[__--MUD--__]]

Thats why they gave us knock sensors. I run regular in all the cadillacs in our fleet. No noticable difference in gas mileage logs.

I notice no difference in the H2. My Ram Air Trans Am is premium only.

[TGCOFTN]

I run Shell V-Power Premium in my 6.0 and my 6.2 Liter. The premium you get better miles per gallon ( you pay a little more per tank, but if your going further on a tank of fuel, it only makes sense )

Not to be rude and no offense in anyway, but if anyone is worried over a few pennies difference at the pump a Hummer is the last vehicle you need to own. While I know those few pennies adds up into dollars, still if thats making a difference in your budget, you should be in a more smaller economy car. I didn't get my H2's for the fuel economy.

[glennf1]

The only thing running regular does is the computer senses knock and reduces the timing a little. You loose a little power but if you are just cruising around and aren't burying the pedal, you won't notice the difference.

[KTM640Dakar]

I always run regular in my 6.2L 2008. I had a bad experience with high octane gas once due to water or old gas at a Shell station. Since they don't turn over the high test gas as often I feel like it has more time to go bad and/ or absorb water due to the ethanol they put in it. Besides if you pay 20% more for high test and only get 3% better mileage then you waste money. My H2 has gobs of power so the regular gas has been fine.