View Thread: Octane


Lotus
OK ive been under this impression for a while now am i right:

Most engines are not able to fully utalize the potential of 89 octane. right or wrong? And higher ocatane (93) seems to run better because of the additives in it? high octane for the most part is a scam? and very few engines can compleatly utalize the potential of 93 octane?

there is of course exceptions, high preformance engines(like the cars allot of you assholes have :curse: :curse: [jelous]) can utalize high octane, but for most engines 89 is more than enough, am i wrong?

The 18th Letter
Octane is the fuel's resistance to pre-ignition (detonation). Most N/A (under 10:1) cars doesn't need more than 87 octane. Some N/A engine with higher static compression ratio needs high octane (93+) to prevent pre-ignition. Those engine with higher than 10:1 will benifit from high octane. But those with under 10:1 will not see the benifit of high octane. Turbo engines needs 93 octane too prevent pre-ignition even with lower (than n/a) static compression, bute because air is forced into the cylinder, making the dynamic compression really high.

Basically, low dynamic compression doesn't need high octane, high dynamic compression does. I hope I got it right. :redface:

Horus
...to fully utalize...And higher ocatane...few engines can compleatly utalize...there is of course exceptions, high preformance engines...[jelous]...
utilize*
octane*
completely*
there are* of course..performance*
jealous*
:slap: :fro:

Lotus
utilize*
octane*
completely*
there are* of course..performance*
jealous*
:slap: :fro:

well arent we feeling special, picking on stupid people :rolleyes:

Rotary Boy
yeah your pretty right. there is no need for kids with stock civics to fill up on 93 to try and be cool, they think it makes them faster but I promise it doesn't.

however one important thing is where you buy the gas.

swifty, thorton, cherrygas and other places that are generally cheaper than everywhere else no matter what prices are.

if you are sporting a car that requires 93 octane, get the 93 from chevron, conaco, 76, BP, amaco or marathon stations.

the gas is better, same octane, but it has chemicals in it that clean intake valves, feul lines and just generally make your car run cleaner.

Sia Bani
I hate Cali's restrictions...

k6kicker
looks like i ened to look up the compression on my ka...it says premium only everywhere all over the car and manual tho...so thats what i have been going on...the z always gets the ebst ic an find

Sia Bani
oh and understand that if the car isn't tuned for running on high octane, you're waisting your money.

My dad used to fill up the old suburban with 92 (at the time) because he thought it was better for the car (it was a leased one too :chair: ). If the car doesn't need it, ie not tuned for it, don't waste your money.

But I'd have to believe what RB says about the more expensive stations like Unocal etc..having added chemicals that are good vs Mom and Pop's reg gasoline.

k6kicker
i can notice a differnce int he s14 tho on cheaper gas, the topend just desnt seem to pull as strong and ill get 20~25 less miles on a tank

Rotary Boy
then it is tuned for higher octane gas

k6kicker
hmm and the compression is only like 9.5:1

Rotary Boy
so, that doesn't mean anything if the timing is adjusted to take advantage of higher octane gas.

A-Tech
the higher the octane, the slower the fuel burns. thats why with high octane gas you can retard your timing alot and get higher speeds out of your engine.

Mr.Dave
What about diesel engines? Are there any stations that would be better than others? I've ALWAYS gone to BP for any of my fullups, which are few and far in between. Not to mention the place is only 3 miles from my house.

When it gets warmer out I'm going to head up to Deleware OH to pick up a mix of B20 or B100. I've never ran that stuff yet, but hear it does wonders for the fuel lines. Just reading about it really excites me. I'm sure it's worth the money. :thumbsup:

CLK-GTR
do you guys not get optimax?

the stuff we get over here is 98 octane although i know you guys measure it slightly differently.

scubie02
do you guys not get optimax?

the stuff we get over here is 98 octane although i know you guys measure it slightly differently.

I think thats like 30 octane American...

:p

CLK-GTR
I think thats like 30 octane American...

:p

well i know we DO get better quality fuel here, but i was just wondering by how much! :fro: