Octane read

Heads, valves, pistons, rods, crankshaft, etc...

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Legacy777
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Octane read

Post by Legacy777 »

Really good article on octane & timing.

http://www.hotrod.com/techarticles/72498/
Josh

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1990 Legacy (AWD, 6MT, & EJ22T Swap)
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Brat4by4
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Post by Brat4by4 »

Very interesting. We can get 94 here. You can get 104 or something ridiculous somewhere around here and i've seen it at pumps in NC. I guess I won't dump any booster on top of these grades. It's usually cheaper to get a tank of 94 than to get 91 + a bottle of booster.
1993 WMP BC6 5MT EJ22T 9psi 3.9:1 213k 205/55R16

62.6 m/s @ 0.66 bar. Gotta love boost. :)
ciper
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Post by ciper »

But most off the shelf octane booster is designed to raise octane by one point only, from 93 to 93.1 not from 93-94! Its a waste of money.
Brat4by4
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Post by Brat4by4 »

First, you have to buy the right stuff. Stores have stuff listed as "off-road use only" that is much stronger than "street" formulas. Plus the article points out that it helps crappy California gas combust better. So if you are stuck filling up with 91 octane it should help a little if you are going to the track or something.
1993 WMP BC6 5MT EJ22T 9psi 3.9:1 213k 205/55R16

62.6 m/s @ 0.66 bar. Gotta love boost. :)
eastbaysubaru
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Post by eastbaysubaru »

All I have to say about this subject is that Californian drivers gets screwed royally. We used to have 92 up until ~2 years ago when everyone changed to 91. Why we can't get 92 or even the 93 that other states get is beyond me. Especially with the number of drivers out here. Another GREAT benefit of living in Cali.

-Brian
'04 PSM FXT
Legacy777
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Post by Legacy777 »

It's all driven by emissions.....I don't understand why higher octane is worse on emissions.....

I know why they only have 91 ocatane in higher elevation, and it's because there's less air, but for forced fed engines....you could probably benefit from the higher octane, regardless of elevation.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
vrg3
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Post by vrg3 »

It's not about emissions; it's the general market...

Gasoline starts as a mix, and then they have to separate it out into the various grades. Here on the east coast, relatively little premium fuel is sold. So, they separate it out into a little bit of high-octane premium and a lot of low-octane regular.

In California, lots of people pump their cars full of premium fuel. So, they have to make a lot of premium as well as a lot of regular. That means that the premium fuel just can't be as good, since there just isn't enough to go around.

This is a simplification, but you get the basic idea.
scottzg
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Post by scottzg »

thanks for giving me one more reason to hate all those people who drive their BMWs 20 mph under the speed limits!
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