I'm in San Diego at the cross section of the 8 and 805. Is there any gas station, hot rod shop, etc that has a pump with any unleaded gas better than 91? I'm looking for anything in San Diego. If there is please post the street intersection and/or directions.

 

What the... You only have 91 Octane gas in Cali? We have 93 Octane over here (Kentucky).

 

Most stations here in FL have 93 also......Shell, Amoco, Texaco....to name a few.......

 

new jersey 94 octane!!!

 

That's weird. I mean with the modding scene being so big over in Cali, it's hard to believe that your "premium" gasoline is only rated at 91 octane. I always thought 93 was standard of premium. I guess I need to get out of my state more.

Holy crap, NJ has 94? That must be an FI modder's dream.

 

They have always had 94 octane where im from... i always run Sunoco 94.

 

There is a 76 Station in Laguna Niguel that sells 102 on the pump. Haven't been there in a while I forget the cross street.

 

most of the sunoco's i've passed recently don't sell 94 ultra anymore -- guess i'll just have to look harder!

 

Most of the Sunocos pack the bigger octane numbers, look around. The Sunoco near me on US 27 sells 110 octane at the pump.

 

In san diego, my buddy hits up a station down there, (i think sunoco ??). I know up here in the dust bowl of hell, the IE, there's a 76 in norco out by norco RCC that has 100 octane at the pump

 

Sunoco 94 here. Another gas station sell 110.

 

How much more expensive is Sunoco gas with that high of an octane? Over here, gas is steady at $2.06 a gallon for premium (93 octane).

 

Yea the unfortunate thing is the 94 octane is a bit steep. I think the last time i filled up with 94, it was around 2.30 a gallon. 93 octane was around 10 cents cheaper.

 

It's funny too because cali has such strict emissions, and yep, we get 91. I'm not sure if you can get 93-94 but there are some stations with 100 octane, but then it's like $5 a gallon or something crazy.

 

94 in CT, one of our sunoco's has 102, kinda weird..

 

yeah here in cali, we used to be rated at 92 octane, then a few years back, they dropped it down to 91. I dunno why they did that, but the true difference between the two grades was only a few percent, since 92 wasn't true 92, it was 91.something or other.....
we get **** gas out here in cali, you east coast guys are lucky

 

sorry for the noob question but was is the benefit of higher octane gas?

 

yeah of course , in high octane gases theres more oxygen thus burning quicker and giving more power to your motor , plus its filtered so much better

- wish i lived in japan 100 octane is like the regular haha

 

so no one knows a local pump with anything better? I don't want to use leaded 110...

 

Contrary to popular belief, high octane gas does not burn stronger or have more explosive force compared to lower octanes, nor is it (to my knowledge) "filtered" any better than lower octane gas.

When a car starts knocking, this means the gas in the cylinder is getting too hot too fast and is thus combusting earlier than it should (before the spark plug fires). You don't ever want the gas combusting on its own; you always want the spark plug to cause it. If combustion occurs too early, you can destoy your engine as it is extremely hard on the engine. So, when a car's knock sensor detects knocking, it immediately retards the timing. This solves the knocking problem, but it unfortunately also causes a slight loss in power.

This is where higher octanes come in. What high octane gas does for you is that it must reach a higher temp before it combusts (explodes) compared to a lower octane gas. So if you're running 91 octane gas and you are getting knocking (and the resulting retarded timing) this means your cylinder temps are getting too hot too fast for the octane your are running. Since a higher octane gas can handle higher temps before it combusts, it will be able to resist combusting before the spark plug fires. You just keep increasing the octane until knocking stops. Continuing to increase the octane beyond that won't do anything for you.

That last sentence is one that I think a lot of people don't get. Your car's computer can only advance the timing a certain amount. After it has reached its timing advancement limit, that's as far as it can go. So, for example, if you're running 93 octane, and you are getting no knocking, and the computer has advanced timing all the way... then going up to 95 or 100 octane will not gain you any power.

The trick is just to find at what octane you get no knocking, and stay there. There's no need to spend more on higher octane. I can guarantee you that a 350Z will not gain anything from 100 octane gas. I imagine 93 might achieve peak performance. The only way to prove that, though, would be to hook up a scantool and look at the knock sensors while you are driving to see if they are activating. And I'll bet most people don't do that.