I recently purchased a 2005 VHO edition Silverado w/ the 6.0L HO.
After my first tank of free dealership fuel, I filled up with Chevron 89 oct fuel.
It ran fine as the first tank.
The next tank I decided to put some Chevron 87 oct fuel. I believe that was a mistake, as I received valve chatter or detonation under mid to full throttle power.
There after I only put 89 oct fuel with no more problems.
I was told by the dealership service department that the 6.0L HO engine can run on 87 oct fuel with no problems. Even the owners manual didnt advise me to use 89 oct or higher.
So what's the deal guys/ gals?
Should my truck have to run on 89 oct or higher?
GAS IS HIGH & RISING!!!

Thanks,
Jim

 

The LQ9 needs 93 or better, it should sat it inside the fuel door. I know my SS says it there.

 

I know all of my vehicles, old or new, have never liked 89 and lower i always use 93 octane. Why not, it saves gas mileage, it keeps you from having to service parts sooner, it keeps the fuel injectors cleaner, its just all around better. Put this way we all know the saying you get what you pay for so... You get what you pay for!!! Why buy the nastiest of the trucks and spend all that money on it just to go cheap on the gas or oil for that matter!! its like seeing someone in that brand new Benz and you see them pull into there little condo/apartment

 

Yep - you had the "DET"

We get our gas from Tucson and SoCal. I can tell you that any octane Chevron will DET - have no idea why but its the worst out there for it.

Stick with higher octanes and stay away from Chevron.

OH - and never fill up in Cali with a turbo car - there is an additive in Cali that will make a turbo car DET upon start up!

The best we get here in AZ is 91 tractor **** - that all I use.....well that and 5 gallons of C16!

 

i have an '04 VHO. the stock timing is so low that 87 is fine in most cases. after a tune, you will need 93 though. I would run 89 to be safe

 

Same additive is in AZ... They add it in the summer. If your turbo car/truck is tuned on it, you'll be fine.

 

the bill passed last year - this years summer gas will be just like the winter gas! No Additive!

the turbo car is tuned on lots of boost and timing with C16 mix - so no issues with the pump gas - i still have the pump gas maps, i just never go back to them unless I run out at the track and they run out of race gas!

 

BTW - I think I have seen you at the shop before with your truck.

Didnt you test a CAI from a local company that lost power?

Oh - I luv those trucks!!!!! trying to convince the wify into one - but she isnt hearing it.

 

Not true. I've run a hot tuned subaru with CA 91 octane and never had a problem passing emissions or making power. Of course I could do at least 40HP more on 100 octane. It's all in the tune.

 

Hey Drew....Nice Numbers!

If you need anymore assistance or dyno time just hit me up!

Please remember - those numbers are AWD which has a HIGHER drivetrain loss than say just RWD.