Octane for 2008 H2 with the 6.2 L

[StockStar]

Originally Posted by Easy Ed

Out of a 2009 Owners manual, page 5-5

Gasoline Octane

Use premium unleaded gasoline with a posted octane rating of 91 or higher. You can also use regular unleaded gasoline rated at 87 octane or higher, but the vehicle’s acceleration could be slightly reduced, and you might notice a slight audible knocking noise, commonly referred to as spark knock. If the octane is less than 87, you might notice a heavy knocking noise when you drive. If this occurs,use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you could damage the engine.If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service.

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[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.