legacycentral bbs

Owner's manual say 87 or higher.

From my online research, I understand that is actually better to use to lowest grade your car can take and that a higher grade is not cleaner or whatsoever but made for muscled or tubocharged cars since the compression is lower.

So the lowest grade allowed should be the most efficient for the engine....thats what I read and understood...

Anyway that said, I feel like 89 works best for it! And I do a hella lot more mileage with it. Maybe it is because the car is old?

Yes it's possible I think it's a indication that carbon is ontop of the piston which increases the compression ratio therefore the knock sensor possibly picks up some knock.

Id check out your knock sensor for cracks!

To clarify, do you have a turbo or non-turbo charged engine?

Turbo charged engine requires 91 octane minimum. Non-turbo charged engine only needs 87 octane.

non turbo.

YEA DAMN GAS OVER 5DOLARS A GALON FOR 91

Falken-18c wrote:YEA DAMN GAS OVER 5DOLARS A GALON FOR 91

That's summer time for ya'!

When I think it used to be 5o cents or less a gallon....but I lived in Europe back then anyway....I would buy a firebird or a chevelle right away!

I would say go with the cheap stuff if you can get away with it. Especially since it is supposed to hit 5 bucks a gallon by july 4th (Drill baby, drill.... but thats off topic)On my 1998 RS i to noticed a difference in how the car ran between 87 and 89. Not so much in fuel economy but how the car idled. Idk if there actually was a difference but thats what my butt dyno said. In california the octane only goes up to 91 as far as normal pump gas goes but in oregon you can get 93 all day for the same price if not cheaper without our crazy taxes. A friend of mine has a 700hp 1.8L integra that only runs on 121 octane!!! Its tuned incredibly well so it get about 25 mpg off boost, but that doesnt help the fact that it costs about $28 a gallon for him

Higher* compression needs higher octane, and of course turbos.

I've never heard of any real problems with running slightly higher octane, certainly don't need premium, but I don't see why mid grade would matter. And gas prices, big whoop, you're spending $50 on a tank, what difference is $2 for the next grade up gonna make?

If it doesn't run right on 87 though, there's something wrong.

92 legacy 147000 miles, i was using 87 and was having LOUD pinging\ knocking noise, started using 89 and don't hear any noise. Maybe it has something to do with the octane after all ( non turbo )

If you're getting pinging/knocking on 87 octane fuel, you likely have carbon deposits in the engine or some other mechanical issue. It should run fine on 87 octane. If the 89 works, stick with it, but it may be masking an issue.

seafoamed it, popped a quick acceleration in 2nd, and something unclogged!:D Been putting 87 chevron with techron since then, and its back to normal. Less pitching sound around 3k rpm, and abit more juice in 5th so far so good

Good deal!

Oh man, it is just getting better and better, my 5th opened up today, before it was worthless, now it actually breathes and purs and accelerate!!! I just keep being amazed by this car, 235k miles and runs like new besides a few fixes here and there