Gas

[S13Stillen]

will preimium gas affect hp? i know higher octane will produce better eevry thing but by how much? i put reg unleaded 87 oct. it recomends premium 92 oct i believe but does the performance really increase? by alot? should i switch to better gas? i use arco what do u use.

[Titan]

Higher octane won't neccesarily give you more power.

I know many people who produce better power with lower octane (i.e 87) then with higher (i.e 92+).

The reason people use higher octane is because it requires higher compression/heat to ignite, therefore useful in higher compression engines (i.e. turbo, etc.) to help avoid detonation.

[whateverjames]

if you use too low of an octane, the knock sensor will have the ECU retard the timing. and you may lose a few horsepower. so the use of higher octane won't give you more power, but using lower octane will take away power, since the engine was made to run on high-er octane.

some cars do run better on lower octane. they did a test in a magazine and certain cars like the accord and mustang ran better on low octane gas.

[SR20Fastback]

arco gas blows, my car doesnt need premium (so I stopped using it) and switched to 89 octane. I also never use any other gas than chevron.

[misnomer]

Arco and other cheap gas tends to leave modifyer deposits in the combustion chamber, you will typically see a crusty white buildup on your spark plugs as an indicator. Chevron, Shell, Texaco. . . whoever else, tend to burn cleaner and will all in all be better for your engine.

Octane really doesn't matter unless you have a higher compression or turbocharger. You won't notice a performance difference. I typically buy 87 octane Chevron.

[reverofe]

when using a lower octane lever, is there chance that it might retard the timing on the ecu and cause the car to release exhaust gasses more than it should?

The reason being is that, I let my dad drive the car for a little bit and he decided to gas it up. I have always put 91 octane gas in there but he put 87. Now the car doesn't pass smog. Everything is in good condition though: the cat, engine compressions, engine's not burning oil. I'm gunna put some fuel injector cleaner next time I gas up and see if it pass smog after that. But will putting the cleaner solve the problem?
Thanks