SI with 87 octane gas *Threads merged*

[xrs54]

WTF? No 91??? Move to a better place!

[huanqi]

Originally Posted by JDMlunatiK

no wonder...that's what i was thinking. but yeah my friend got like a full tank of 100 oct saved up in his garage as a present for his birthday. is there an expiration date or time you should use it within before it becomes bad?

gasoline expires, please tell him do not store it in his garage and wait for the right day to use it...

[GordonTse]

i talked to a honda tech(co-worker) and he said it's fine if you put mid-grade(89) in, that's what he runs in his FG2.. he try'd 87 regular before and it knocked..

[icewildabeast]

87, it'll knock, and the timing will be retarded (not to be mistakened with the "idiot" retard, but timing set back), and then you'll lose power, and then everything "will be fine"
Just putting in 87 once is not going to do anything to your engine. Drive it normally (not spirited/vtec) and it wont even have to retard timing.

I can say all of this out of experience.
I did a test, was putting in 87 octane for 3 months. Only noticable difference was loss of power after my first time knocking (hard acceleration in high heat environment). Sort of felt like AC was on, without it actually being on.

when i put 93 in again, i didnt feel any noticable difference until after about 2 1/2 tanks when i believe the timing was back to normal again.

[killsw1tch]

A little pinging isn't that bad. My Dad had a truck for 20 years that didn't ping with 91 octane yet he always filled it with regular 87. It would always ping under load yet the truck lasted a long time with no problems.

If you can't hear it pinging then don't worry about it. The car automatically adjusts it's timing anyway when lower octane gas is used.

[soxfan143]

Originally Posted by jdm free

imho i think the whole "i need 93 gas or my engine goes kaboom" shit is all bull. Ive driven my gsr wit 120k on it for probably 10k miles using 87 octane and no knock. and that was beating the shit out of it.

i drive my si the same way whether its 87 or 93 octane. i dont develop a knock and runs the same way it does when i bought it, when i put 93 or 87 in. ive talked to honda, mercedes, and infiniti techs and theyve all said it really wont make too much of a difference if u dont put 93 in it.

i dont care too much to put 93 in since its only like a buck or two more than regular 87 octane anyway

This is the furthest thing from a bull sh*t subject. You need to educate yourself a little better before you start spreading horrible information to impressionable people on here. Or you will cause serious damage to peoples cars. Do you have any automotive credentials to back up your claim here bro other than a couple of retard techs "opinions"? Not all techs know what the hell they are talking about. And this is basic engine knowledge. Why do you think built race motors with high compression pistons and high boost motors HAVE to run higher octane fuel? They sometimes can ONLY run race fuel for it's extrremely high octane ratings. It's not just for power. It's from the super high pressures in the combustion chambers. And an 11:1 compression ratio is extremely high for a street driven production car. Most cars are around 10:1. And even that's a little high.

And the knock sensor doesn't really control anything it will just "hear" detonation and this will tell the ECU to retard ignition advance and add fuel. And when it's cold outside the cooler air will cause detonation even more because of the higher concentration of oxygen in the air which will burn all that much faster and better and there will NOT be enought ignition retard available to stop this. So if you want to play with fire to save a few pennies then go for it. I can understand if you have no choice but don't use more than a few gallons. Just use enough to get you somewhere that will have the proper octane fuel. Or go get some octane booster. Even though that stuff is pretty much a joke. But it will help enough to keep your motor in one piece.

[w00t692]

^^ he's correct. This car requires 91+ octane through compression alone. Timing is another thing they tweak to require higher or lower octane ratings (thus boosting power) But you can't really tweak this as much at 11:1. But there are 10:1 and stuff inbetween 10:1 and 11:1 that requires 91+ octane because the timing is advanced pretty far from the factory.

Don't put 87 octane in your car ever. If you have to, drive it like a baby, and don't put a full tank ever. Fill it up with small amounts like 1-2 gallons.

[GlxyGry06Si]

go buy octane booster or just drive the car very easy.

[iCeMaN57]

I had the same issues with people running out of gas due to the darn hurricane. Luckily I filled up the day bf and not alot of ppl seem to use high octane

[RWatters]

Originally Posted by mellowbob

Keep a bottle of octane booster for emergencies.

Octane booster is a huge waste of money. It doesn't raise your octane but by percentages of a single octane point.

[w00t692]

I would imagine. Even if it was 140 octane and it was 1 whole gallon out of 15 gallons it would make the gas go from 87 octane to 90.5 octane mix.

Now, it's obviously not a whole gallon. And i doubt it's 140 octane...

[GlxyGry06Si]

Originally Posted by RWatters

Octane booster is a huge waste of money. It doesn't raise your octane but by percentages of a single octane point.

yes for most of them. there are some very strong ones tho that will raise it a lot tho.

[bsbabcock]

Ok, so yes I will do a search here, but now we're on the subject..

Which octane booster?
Are any octane boosters safe or to be avoided?
Booster dangerous for the Si engine in particular?

Thank goodness I hope this would be a very very temporary thing. Worst case 1 tank-full.

[JDMFGSI]

i agree with soxfan...

[GlxyGry06Si]

Originally Posted by bsbabcock

Ok, so yes I will do a search here, but now we're on the subject..

Which octane booster?
Are any octane boosters safe or to be avoided?
Booster dangerous for the Si engine in particular?

Thank goodness I hope this would be a very very temporary thing. Worst case 1 tank-full.

just read the bottle and see which one is the strongest. I dont think there are any ones that arnt safe or that we should avoid. they all should be safe.

[fordtraitor19]

Originally Posted by JDMlunatiK

dude...how much is 93 octane where you guys are? you guys talk about using 93 octane as if it were to be 87. i've yet to find a gas station here in orange county where they have anything more than 91.

no 93 in so cal for the lose.

[4door]

i agree with soxfan.....you guys that put 87oct in, don't plan on owning your cars very long....but us peeps that plan on keeping are cars use 93...

[huanqi]

mmm i use 91...i dont think there are any 93 octane in the LA area. LOL to whoever said they drive their GSR and Si the same...what point does that make? two complete different cars with 2 complete different compresion ratios. What you said dont make sense. For your own protection, i hope you start putting in the proper type of fuel your car needs, no one on here wants you to learn it the hard way.

[e_man]

^lol agreed

[bludragon]

I would say, if you have to use low octane, then don't use full throttle, especially at low revs... except at high altitudes where it might be ok.

Another issue would be the variation of actual octane - if the variation is such that the 87 actually turns out to be 85, then expect problems...