Octane for 2008 H2 with the 6.2 L
 

Hi, can you damage the engine if you use 87 or 89 octane with the 6.2 L engine, because I heard that premium fuel is recommended.
Thanks.

Re: Octane for 2008 H2 with the 6.2 L
 

What does it say in the owners manual? The 03 6.0L is set up for regular fuel.

Re: Octane for 2008 H2 with the 6.2 L
 

Ed Wallace an auto guru in the DFW area who drives and tests many of the new cars, says that he hasn't put premium in cars in years, regardless of what grade it calls for. He says that you may get slight reduction in mileage and power but it runs fine.

We have run my wife's Lexus on regular for years and it does just fine.

I however, still run my 505hp Corvette and 09 H2 on premium.

Ed Wallace's website is insideautomotive.com

Re: Octane for 2008 H2 with the 6.2 L
 

No, read the owners manual if you have it! The recomended fuel is regular so 87 octane fuel is fine and will not damage the engine. I am on my 2nd H2 and have never run anything but 87.

Re: Octane for 2008 H2 with the 6.2 L
 

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.

Re: Octane for 2008 H2 with the 6.2 L
 

:clapping: ^

Re: Octane for 2008 H2 with the 6.2 L
 

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.

Re: Octane for 2008 H2 with the 6.2 L
 

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.

Re: Octane for 2008 H2 with the 6.2 L
 

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

i use only 93 v-power.

Re: Octane for 2008 H2 with the 6.2 L
 

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.

Re: Octane for 2008 H2 with the 6.2 L
 

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.

Re: Octane for 2008 H2 with the 6.2 L
 

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.

Re: Octane for 2008 H2 with the 6.2 L
 

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.