My Silverado has a Hypertech chip in it so I have to run premium in it and there's always a 5 gallon can in full in the bed. I needed some gas last night but went to the pumps and put in $4.50 worth of regular. The owner's manual says "at least 87 octane." Is there any benefit to premium in these engines? Any harm?

 

None at all.
Just to your wallet.

 

Seriously Doc...... you figure that there's absolutely no difference in using premium vrs regular gaseline ?

You mean I've been wasting my money on the "good stuff" all this time ??.....lol

 

the higher octain in premium dosnt add any performance or take any, the higher octain keeps the gas from prematurely detonateing under extreme pressures like in high performance cars. only harm is to your wallet

 

you need to up your octane when you up your compression. untill then regular 87 should be just fine unless your hearing pinging. Its just like spyder6 said. If your compression goes up you can combust the fuel without the spark if the octaine is too low. Just like a diesel engine has no spark plugs it uses very high compression to detonate the fuel. I moved up for my wolverine when i went to a higher compression piston. I could probably run 89 and be fine but i just jumped to 93 because I dont get to ride that often and better safe then sorry

 

It does nothing for performance, all it does is keep it from pinging. On the otherhand if you use 87 it may harm o2 sensors or air fuel ratio sensors. As for the 500ho just use the cheap stuff!

 

I appreciate all in the info guys!

 

Well I will try to give you a short version of this :
premium gas was and is designed to protect your engine against detonation. and it does this because of the chemical makeup of long branch tightly bonded molecules. Where regular gas has a molecular structure that has less of a bond.
The chemical composition of the fuel determines how fast the fuel will burn and if it will work well with high compression or temperatures.
fuels with weak molecular structures [regular] will break down more quickly or burn spontaneously [detonation] at lower temperatures.
Fuels with tight molecular structures [ premium] burn more slowly and take more pressure and heat to fully break down and burn.
therefore putting premium fuel in a engine not designed for high octane fuel [I e not having high compression or spark advance ] will not be able to break down the chemical bonds. And will not completely burn the fuel charge therefore produce less power.
So you see next time your at the pump buying that 115 octane racing fuel for your sled that costs five dollars a gallon. you may want to reconsider. And by the way no fuel can be over 100 octane ! It's a percentage
Run the type of fuel your manufacturer recommends !!!!!

 

Information on fuel and octane

From this site on a earlier topic. Lots of great info.

SLG