1hot88drop50

ya think? lol And out here in the Golden State gas is 2.15 for 87 so im thinking about putting some 3.73's and drag radials on a 10-Speed..

vfast

I use 89 with 14-15 degrees.....and to all that used 93 on a stock engine the oil companies thank you as it does not do anything and could so you down due to your engine/spark not being able to burn all the fuel effiectly..93 burns at a slower more even rate then 87...when you hear a knock then 89 will be needed....

Dbeck002

Sorry to be such a Niwbi but what timing are you guys talking about? Enlighten the automotively challenged.... Duuurrr....

mdvaldosta

Octane rating has nothing to do with the quality of gas - the Oil companies rating system (reg, mid, premium) are VERY misleading. Sometimes, but mostly not, their are better additives in the premium gas - but as far as octane rating is concerned, the higher the octane - the more resistance to ignition the fuel is. If you have a problem with the fuel igniting too early (spark knock, pre-ignition, detonation - whatever you wanna call it) then going to a higher octane fuel will slow the flame speed down and be less likely to knock.

On the downside, if you use 93 octane when your setup only needs 87 octane - then your NOT gonna get complete combustion - all the gas will not burn in the cylinder - causing a slight loss of performance and potential long term damage to your cats and 02 sensors, as well as increased carbon build-up in the combustion chambers.

bobby

do u guys think i should switch to 93 octane wiith my mods listed below just to burn cleaner or just stick with 89, thanks

FoxGT

If it's not knocking don't switch gas grade. It's just a waste of money. Dbeck002, we are talking about ignition timing, when the spark plug sparks after or before TDC.

mdvaldosta

You got it backwards, as do most people - thanks to our wonderful corporate oil companies mindfvck jobs. Using 93 Octane when you only need 89 or 87 will actually cause you to NOT burn as clean, you will burn LESS gas and expel MORE gas into the converters and out the tailpipe. Octane rating has NOTHING to do with fuel quality or how clean fuel burns, it is only an indicator of its burn rate.

1hot88drop50

Preach it MDV!! not many know that 87 octane is sometimes what cars preform most efficiently on.