like it says, what does it do to the engine? why is higher better?

race gas (like 114 octane and such) lets you run shitloads of boost because it's more resistant to detonation. from what i hear, high octane gas is also of a higher manufacturing quality and results in more stable air/fuel ratios.

In a nut shell, higher octane equals to slow, and controlled burn. For a sotck NA motor, it does nothing. For a turbo/NOS/Cammed car, they aid with preventing knock and detonation.

anyone else?

Yeah but your car needs to be running right. The idea to push it more with better gas won't protect you if you are running rich or lean. And like it was said, it doesn't do much for a NA car.


http://www.cardomain.com/id/jasvbts2k2
"The ONLY Honda I'd mod would be ASIMO"

in short and simple terms. Its harder to ignite.

it is hard to ignite but when it does it burns hotter the regular gas. Its also creates more of a explosion which will help push the piston back down in the cylinder.

>it is hard to ignite but when it does it burns hotter the
>regular gas. Its also creates more of a explosion which will
>help push the piston back down in the cylinder.

aahhhh... now that makes sense....

kinda funny i did a test with to the drags with unleaded ran my best time..then went back and ran shityer <(dont think that is a word) times with high octane...bad luck but seemed the gas did not help...

what about emissions? which gas would create cleaner emissions? jus wondering cuz i got smog check by the end of the month.

unleaded gas makes better emmisions but the higher number ones like 94.... but to get a better pic of the higher octane gases leaded on non-leaded read Turbo mag this months issue... it has a full break down

This is how I understand the whole octane thingamajig, so someone correct me if I'm wrong. The higher the number of the octane, the slower it'll burn off (more fuel onto the combustion chamber). This means you'll run even more rich, we all know how rich we run from the factory ;) Running more rich causes you to loose even more power.

well yes and no. Talking about octane and fuel burn can take a whole lot of typing. Like mentioned above ^ you should read up on it. The use of the term "explotion should be used loosely, engines dont explode gasoline( unlesss something goes wrong). Detonation is sort of an explotion. This is something we want to avoid. Higher octane burns slower ( when comparing to other fuels, and relatively speaking), this is what we want. A slow controlled burn downwards from the spark plug to the piston forcing it down. Detonation is caused by several factors, mostly though through over heated components that retain that heat and then ignite lower octane fuels ( easier to ignite). The damage occurs when either the piston is on its way up and then the ignition occers caussing a huge force on it contrary to its upward movement ( maybe caising it to give and go through your block, or hammered by the remaining parts). Also it could cause the 2 wavefronts to collide, the ( the spark plug ignited one and the one caused by the heated element) this would cause havoc also. Ill try and draw something up but cant promise anything.:thumbsup

i will always use the highest octain at the pumps, and i stand by this firmly... when ever i used low rated gas my car ran like shyt!!!

i've noticed this with more than just my car, mom mom's van, my 2 previouse cars also.

with my mom's van u can hear knocking noises allot!!! she told me she put low octain gas in... the next time she filled up she put the high in and it ran fine again!!!

i don't know how it works but as long as it keeps my car runn' strong i'm happy

WTB--- Dodge Omni:


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mods:
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doesn't burn all the way and clogs your cat. (if your are stock or very lightly modified)... if you upped your compression or put a turbo on then higher is better, more resistant to detonation, but otherwise, you are just wasting money for something that won't burn all the way

higher the oct. the less det. because it takes longer to burn in the engine

Higher octane burns cooler, thats why it helps prevent detonation. if you dont have forced induction(where you turn up the boost with high octane) or high compression(allows more timing) then you are wasting your money with anything over 91-93 octane pump gas.

1997 Silver RS
Wiseco 8.8:1 Pistons(back to low compression!)
Eagle Rods
T3/T4 Turbo
Custom FMIC
Greddy Exhaust
440's
Most current 1/8th mile time: 8.3@90mph 2.015 60'(Nitto Drag radials, i suck)

My understanding of Octane ratings:

The octane rating is based off of a comparison of Pure OCTANE. thus 93 octane would have the same result as 93% Pure Octane. Now what it does differently. As your car pulls air in it mixes it with fuel. This mixture of fuel and air is now compressed. Now the goal here is to get the most compression without causing the fuel to ignite due to pressure. Thats the job of your spark plug. The lower the octane the lower the compression level can be before you would get detonation. But the higher the octane the more compression we can have before we end up with detonation. So overall the higher the octane the more potential power can be outputted and the safer it is to do so. Please correct me if Im wrong.

i've read all the details in everyones post but i have one simple newbie style question/comment to add:

the theory on running high octane being a waste because it wont all burn off properly and is pointless on a lightly modified car makes sense. however, if one were to run say two ranges hotter of a plug than stock, couldnt they in theory do a more efficient job of burning off the higher octane gas?

tia

also, the engine reads that the fuel is better and can retard or advance timing as it sees fit and thus creates more power also.