SI with 87 octane gas *Threads merged*

[FFtouge??]

by the way, where do you get 93grade ...?
all i see is 91....

where can i get 93grade in so cal..?

[noshownogo]

we have 92 and 95 in Trinidad but the price for 95 recently shot through the roof so everyone is contemplating going with 92. Mind you, our quality of gas has been skeptical and 92 may very well not be 92 but something a bit lower.

My question is, is it safe for the R18 with a 10.5 : 1 ratio to run 92/91 grade gasoline? Does anyone else currently do this with no pinging even under load?

[rmfa]

I can see doing this if you can't find the premium. If you are doing this to save 2-3 bucks, your an idiot.

[Sle]

^ you know how much 3 dollars can get you off the dollar menu? haha jk.
yeah its well worth the extra 3 dollars knowing that your car is gonna
last for a good time.

[mattellis]

well ill be the first to say this i have to run 87 right now in my car, and ill be the first to say you can tell a loss in performance. i live in nc and we are in a big gas shortage and all the gas stations are only getting 87 since its in high demand but soon as i see 93 or 100 get back i will be running that asap!!!!

[MrWildBill]

I wish we had something other than 91 here in AZ. I miss the 93 that was available in FL. Has anyone used anything like 100 + octane (full tank) in their Si? I was thinking of going to the track and filling up with some. Will it be noticeable and would there be any risk of damage to the engine?

[BSonly]

i usually go to the drag strip with about 1-2 gallons left of my 93 and pump about 1-2 gallons of the 100+. It's too expensive to use a full tank just for regular street driving.

[milestoneiii]

A 10.1:1 compression engine should have no problem running the 91 octane. It should even be safe for close to 89 to 87 for short and light load traveling. I wouldn't risk anything lower than 89 for sure though. If you do use the 91 and feel it isn't right, have it tested. There are several places that can test the octane content and give you an analysis (much like oil analysis'). If the fuel is consistantly off in rating and measurement, use some booster in a full tank and have it re-tested until you find the proper booster to fuel ratio. Sounds like a lot of crap to go through, but it shouldn't take but about 3 weeks of light driving and however long it takes to get a sample of each to a lab. May be on the expensive side, though. Well worth it versus another engine.

4cyl. Chevy S-10's have about 10:1 compression (if not mistaken) and I used regular with never an issue for 7 years. Newer cars may have different results though.

To clear some things up, a ratio of 13:1 compression will have a hard time running smooth off of 93 octane - pump gas. 13:1 Mind you. Si's have 11.1 or 11.3:1 compression. That's perfectly capable of using 91 octane with no problems.

Running higher octane other than 91 may give you some mileage gains, but unless you're running 103 octane you won't notice any difference between the Cal. normal 91 and the other 93 ratings.

[4door]

i hate nc....i'm on empty and i refused to get gas at the BP on 115 and harris blvd, charlotte...to pay 4.90... i asked them if it was a mistake and they said no....it makes me almost trade the si in for a scooter.

[fryrice]

u serious! 4.90 for premium gas!? damn and i though cali has the highest gas prices.

[Nagasakki]

For Charlotte, NC:
I got my 93 at Exxon at E. Independence Blvd.

[Supa Ninja]

I'm in NC as well, I ran a tank of 87......won't ever do that again.


We, Si owners, have to run the good **** because our engines have 11:1 compression. When we run lower octane our engines will knock and ping. Thankfully we have very sensitive knock sensors. When they sense a knock they retard the timing, hence running like ****. If your boosted its even worst, WOT feels like your on a bucking bronco.

Its a serious PITA to find a gas station here thats carring 93 octane. My solution has been to ride my sport bike more (its older, carburated, and Kawi recommends the cheap **** in it)

If you can't afford the good stuff then you got the wrong car, if you can't find the good stuff then that just sucks. Oh ya I put some octane booster in mine and it helped a little.

[RadekWsi]

i think it would only do some damage under high compression, for example 8000rpm
other wisew i don tthink under normal driving conditions it would doo too too much
its still not good for it
i stick with my premium all day haha

[FijiSan]

i HAD to run 89 in my car last week, I didn't really feel a noticable performance loss, but only beacuse i was babying the car until that stuff was gone, the one thing I will point out is the fuel economy, IDK for sure if it's a contributing factor, but the lower octane gas defiantely shot my gas mileage to hell

[agr5]

The fact that people can't get 93 in some places is crazy. Every gas station around me (NE Ohio) has 93. That is the only octane my '08 FA5 has seen. But I would think 91 octane would be just fine.

[EchoHawk7]

yeah i have 93 and 94 in Buffalo Ny, when i moved to phoenix i only had 91 my car runs the same, there doesnt seem to be a difference but then agian i dont race it around town i just casually drive.

[CivicEX]

Your engine called. It wants it's octane back

[Izzyrocket]

is there any record of anyone's engine getting messed up due to low octane? Note: I said low octane, not discount gas.

read the article:

WHY PAY FOR PREMIUM GAS?

[vingavina]

subscribed

[antsmith101]

all I use in mine is 91..