Lower Octane=Better Performance????

[93-240SX-COUPE]

I was just web browsing and I stumbled onto this forum

http://forums.nasioc.com/forums/arch.../t-320627.html

where they say that if you want better performance you should go with less octane. They say that higher octane is better cuz it burns slower and wont mess up your engine but lower gives better performance. I need someone like nissanfanatic to explain this one, unless someone else knows what they're talking about.

[nissanfanatic]

Alright, higher octane fuel does burn slower. In high compression applications, you need a slower burning fuel because there is much more heat involved so the combusion process begins earlier uncontrollably. As anyone knows, compressing air creates heat. Some diesel engines run solely on heat created by compression. Ever tried to light diesel? It really doesn't burn very well at all. With high compression, nitrous, and FI applications, if you use too low of an octane fuel, most likely you will expirience pre ignition and possibly detonation. Pre ignition will raise EGTs considerably and may cause detontaion.

If you try running a higher octane fuel and expirience lower performance, you can either go to a lower octane fuel or try advancing the timing. Looking at spark plugs is a good indicator for the average joe that isn't equipped. Be careful when advancing timing as you can run into detonation if you advance too far.

So the whole thing is "Run the octane appropriate for your application," not so much "This octane is better,"

[johnnyboy5]

what are the pros and cons of !) running on low octane and 2)running on high octane????

[johnnyboy5]

never mind the question, just read the article

[93-240SX-COUPE]

Thanks Fanatic. I knew if anyone was going to explain this to me u sure would be up to the challenge

[nissanfanatic]

no problem