My uncle who sold honda cars pretty much his whole life is telling me that high octane gas is actually BAD for your prelude because it burns the pistons out. That a 4 cylinder doesnt need high octane. I personally dont think he knows what the **** he is talking about because he has downed half a bottle of Crown Royal at this point. Please put this old timer in his place and tell him the truth..........

 

Each piston-type gasoline engine has some minimum octane requirement, below which it will ping. Ping and octane requirement are a function of engine design, manufacturing tolerances, engine condition, specific engine part malfunctions, and certain engine adjustments.

 

when your car pings isen't there a way to hear it when the car is idleing? and why does pinging occur? i don't know to much in the area of ping and detonation.

 

ping is the sound of the detonation. It's best if you catch it at idle.. because the force at WOT is something like 7000 psi when it detonates. Wayyyy to much for your engine.

Oh, and if you go too high of an octane, since it's harder to combust, you'll make your engine burn it slower which i've read can reduce your power production slightly. (if you're running like 106 unleaded when you only need 87)

 

Okay, short story.
There's two ways to get pinging (detination.) Both have the end result of the gas being ignited at the wrong time, meaning too early. The early explosion is what makes the "ping" noise, and is very bad on bearings, pistons, and the head gasket.

One way it ignites early is if there's a sharp corner in the combusion chamber that has heat in it from the last time. It acts as the ignition source instead of the spark plug, so you've lost control over *when* you want it lit off.

The other way is effective high compression. The air gets compressed so much that it gets so hot that it lights itself, like a Diesel engine. Again, it isn't igniting when you want it to.

High octane gas burns *slower* then low octane.