octane rating and engine performance
In Texas, the minimum octane rating is 87. On a recent trip to Glacier, I noticed a lot of the fuel in states like CO, WY and MT, the octane was 85, and you had to buy the mid-grade to get 87 and abov...
Forum Discussion
4x4ord wrote:Sunnysidebeach wrote:
I have an older GMC Sierra, and even with its older technology it adjust the injection timing, valve timing, and ignition timing for different fuels. Under the manifold, is a knock sensor that detects the first sign of knocking and adjusts the timing to make that knocking stops?
My turned up 9.5 to 1 compression ratio 340 HP 5.3 Ltr motor becomes, a 240 HP motor, when pulling a load on 87 octane, I can just imagine what it would do on 85.
So while it will work at altitude, you will feel allot less power from your motor.
With a 9.5 compression ratio engine if you think you can get a 40% increase in power by using premium fuelover regular you're dreaming.
I know, but that's what dreams are made of.
I just put premium in my 5.3 truck (btw Sunnyside, LTR engines are 5.7 350s). Was hoping to gain that magical 100hp.......
And 340hp isn't really turned up. I hope you didn't rebuild it and get less than the new stock ones.....
