Read this thread... explains my argument, and even includes a diagram.

Oy, you Integra owners are so intense...

 

it still has no where in the forum that says that it will damage the engine. I agree that it burns at a slower rate there for it doesnt give as much power but never will a gas that is meant for a engine hurt that engine

 

This is 100% wrong. As a general rule you should be using the lowest level octane you can get away with, meaning whatever the manfacturer recommends, or whatever prevents your engine from blowing up. By using higher grades of octane you are reducing the percentage of fuel that is being burnt since the higher the octane/heptane ratio is the more resistant it is to ignition. Higher octane fuels are neither cleaner nor more powerful. An engine requiring higher octane usually has more power because it has a higher compression ratio. Because of this high compression fuel ignites faster, therefore necessitating a fuel which doesn't ignite so easily as to prevent detonation (octane). If you use a higher octane than the engine is designed for then your fuel won't completely burn and this will increase the stress on the cat converter (minimal but present) and you will gum up your spark plugs. If you have an LS and put 94 octane in you will notice the engine hesitate a lot. You will experience power loss. The only thing you'll be doing is wasting money. Zero benefit.

 

High octane fuel is required when cylinder compression pressures are high enough that fuel ignition may occur within the chamber when the piston is on its way up; pre-ignition. Higher compression ratios = higher combustion chamber pressures = higher heat. At higher temperatures the fuel is burned more efficiently. So, while it’s true that the higher-octane fuel does not posses any more energy than low octane fuel, the increased octane allows the extraction of more of the potential energy that has always been there. Conversely, lower compression ration engines utilize a little less of the fuel energy potential (2-4% reduction) but there is also less heat generated in the combustion process. Also, higher octane fuel reduces engine knocking or pinging. So, if you have a low-compression engine, save the $5 and use 87-octane.

 

I used to run 93 in my LS, because I had to run it in my turbo Acclaim. After switching to 87, my car ran like crap. the 87 around my area is GARBAGE though, unless you buy it from the right place. I found myself running 89 in most cases, that seemed to work the best.

I run 93 in my R though, I can't find 91.

 

i know ive seen at least 3 articles written in magazines or online saying that putting higher octane fuel than what the manual reccomends degrades performance and is generally not good for the car (i forget why, il ltry and dig the articles up)

 

i put 93 in my LS because i advanced the timing... anything lower than 91 and my engine bogs.

 

:thumbup: