Originally Posted by BoilerUpXFire
Every mechanic I have ever spoken to has told me to abide by the recommendation from the manufacturer, they have hundreds of thousands of hours in torture testing every part of the automobile and make this recommendation for a reason.
I bet if you took a look at some injectors from someone using 87 for 30K miles and someone using 93 for 30K I bet it would look like the difference between a smokers lungs and a nonsmokers lungs. Dramatic, maybe - accurate, yes.
The detergents in the fuel will determine the difference you see in the fuel injectors. You will see in data logging and on the head and top land of the piston or your valves/valve seats and your spark plugs if you run to low of octane and it starts blowing up microscopic parts of the engine internals. The Octane number is nothing more than a numerical rating for the fuels resistance to preignighting or knocking or pinging with higher numbers equaling better ability to resist it. On lower compression engines, you can typically get away with using a lower octane fuel because the chances of it preignighting are much lower than if all the variables were the same and it was a higher compression engine. This is why the SRT has a lower compression ratio than the NA. If we both shared the same 10.5:1 we'd have to run a much higher octane fuel because of the higher combustion chamber temps and the fact that we're already jacking the intake charge temps up when it goes through the SC.
Long story short, you might not hear the damage now but you will if you keep doing it long enough. Use the recommended fuel for the car