Moosen Posted March 12, 2012 Share Posted March 12, 2012 How many of you actually run a minimum octane of 90 like is recommended for our eas82's? I have just been running the 85 since i got my car, and just saw that it should be 90, so when i filled up today i put a 91 blend. We will see how it runs. Will i notice much of a difference? Quote Link to comment Share on other sites More sharing options...
Dj7291993 Posted March 12, 2012 Share Posted March 12, 2012 I run 85. I tried mid-grade once, but I got worse mileage, and no real performance difference. But, my engine isn't exactly a shining example either. Quote Link to comment Share on other sites More sharing options...
skishop69 Posted March 12, 2012 Share Posted March 12, 2012 Chances are, you don't need premium anymore. Octane rating is the fuels ability to resist detonation due to compression prior to the firing event. It wasn't all that critical on the Ea82s as it was on the Ea82Ts. At any rate, with standard wear of engine parts, it's not going to matter now since your compression is lower now than when it was new. Back then it might have caused a detonation problem and possibly ate a piston or exhaust valve, but I doubt even that. I ran my Ea82T on regular. Quote Link to comment Share on other sites More sharing options...
92_rugby_subie Posted March 13, 2012 Share Posted March 13, 2012 Where do you guys get your gas? I run regular in mine with an Octane rating of 87 Quote Link to comment Share on other sites More sharing options...
Turbone Posted March 13, 2012 Share Posted March 13, 2012 I run mid (89) in all 3 of mine. The Brat because its high comp. The RX because its turbo. The SVX because its......a SVX Quote Link to comment Share on other sites More sharing options...
AKghandi Posted March 13, 2012 Share Posted March 13, 2012 I run premium in my wag..but it's a turbo so I have to. If I had the cash id put 116 race gas in it. Then turn up the boost. Quote Link to comment Share on other sites More sharing options...
Moosen Posted March 13, 2012 Author Share Posted March 13, 2012 I run premium in my wag..but it's a turbo so I have to. If I had the cash id put 116 race gas in it. Then turn up the boost. ahahaha I wish i had a turbo Quote Link to comment Share on other sites More sharing options...
Dj7291993 Posted March 13, 2012 Share Posted March 13, 2012 Where do you guys get your gas? I run regular in mine with an Octane rating of 87 High altitude has lower octane. Since the air is thinner, compression pressures go down. So, octane is a bit lower, and gas is a bit cheaper than most places. Quote Link to comment Share on other sites More sharing options...
l75eya Posted March 13, 2012 Share Posted March 13, 2012 93 octane in the Loyale. He pings with 89 or 87. 1 Quote Link to comment Share on other sites More sharing options...
92_rugby_subie Posted March 13, 2012 Share Posted March 13, 2012 I thought about running premium in mine.... but a mash the gas, Ill wait til I have a job to afford it... and by then... EJ22T will be going in Quote Link to comment Share on other sites More sharing options...
AKghandi Posted March 13, 2012 Share Posted March 13, 2012 In the 6months I've owned my car I've never put regular in it Which when your delivering pizzas seems counterintuitive lol..especially when my right foot Weighs twelve metric tons. And i Still manage around 20mpg in town. I love my Subaru ...even though it's ugly And old..it still scare the crap out of me sometimes.. I swear it has a mind of its own.. Quote Link to comment Share on other sites More sharing options...
natext6 Posted March 13, 2012 Share Posted March 13, 2012 I drive an xt6, and I can 100% feel the difference between the grades (87/89/91, 91 being the highest consumer grade gasoline available in Canada) I find that with the ER27, which is for all intensive purposes, a 6cyl EA82, the higher grade fuels deliver a much smoother ride, and reduce high/low end vibrations. I also find that the higher grades net a slightly better fuel mileage, but that it isn't all that noticeable. This is just what I've noticed/the conclusions that I've drawn tho, definitely not an expert opinion Quote Link to comment Share on other sites More sharing options...
987687 Posted March 13, 2012 Share Posted March 13, 2012 I've tried running 89 and 91 in my ea81 and upping the timing. It didn't add any performance or gas mileage. It seems perfectly happy on 87. I like turbos until I have to fill up the tank. Or until something breaks.... then it gets expensive really fast. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted March 13, 2012 Share Posted March 13, 2012 (edited) The rating in the manual for the older stuff may not be what you think. There are several ways to calculate octane and it is probable that Subaru listed the octane as the RON (what they list on pumps in japan) and since what we list at the pumps in the US is the AKI number ((RON + MON) / 2) there is multiple points of difference between the two. 87 on our pumps is equivelent to 91 in Japan. You should always use the lowest octane rating that does not result in detonation. There are more BTU's per gallon in lower octane fuels (they burn more easily) and thus your fuel economy will be best with the lowest octane that does not result in detonation or in the ECU pulling your timing. GD Edited March 13, 2012 by GeneralDisorder Quote Link to comment Share on other sites More sharing options...
AKghandi Posted March 13, 2012 Share Posted March 13, 2012 I've tried running 89 and 91 in my ea81 and upping the timing. It didn't add any performance or gas mileage. It seems perfectly happy on 87.I like turbos until I have to fill up the tank. Or until something breaks.... then it gets expensive really fast. Yeah I know that feeling.. Quote Link to comment Share on other sites More sharing options...
bheinen74 Posted March 14, 2012 Share Posted March 14, 2012 I run mid (89) in all 3 of mine.The Brat because its high comp. The RX because its turbo. The SVX because its......a SVX the "US owners manual" says use of premium is required in the SVX, and nothing more than 10% ethanol in that car. it is listed in the manual. Why do you use midgrade, when they require and state must use premium? same goes for the turbo ej22t. the fuel filler door says premium only, so does the dash instrument cluster. My town doesn't even have a gas station, so i fill my Gerry Cans with premium for the times i get low on the SS. matter of fact, not many places within 20 miles sell the premium here I AM in the BOOOONIES> Quote Link to comment Share on other sites More sharing options...
subynut Posted March 14, 2012 Share Posted March 14, 2012 I usually run Premium in the XT6, but this last fillup I put in Mid Grade, but it is not happy with it. There is a slight hint of pinging when it's above 70* outside and the power is not smooth like it is on Premium. I will be putting Premium in it, from now on. My last EA82 I ran regular and it never had a problem running it. No pings and 32mpg out on the highway. Quote Link to comment Share on other sites More sharing options...
tallwelder81 Posted March 14, 2012 Share Posted March 14, 2012 yes, all the power is in the GASOLINE. the additives <more octane=more additives> make your gas weaker, less horseradish. the only reason you should EVER use higher octane, is if your compression requires it. ea engines <non-turbo> have like 8.7:1 compression. my 67 bigblock buick was rated at 10.5 compression, factory. but i ran it on 89 octane, with a bottle of HEET per tank, to keep off the crud. and i suspect the compression was closer to 11:1, due to the pistons i used and my tinkering with the vacuum and mechanical advance. all i know is, it did just fine on 89 octane. i put about 12,000 miles on a 170,000 mile engine, on that 89 octane, and never had popping or pre-ignition. if you are into tinkering ANYHOW, one thing that helps a lot, is to get into your chambers and smooth off any ridges. dont forget the actual spark plug "bridge". it has those sharp square corners. you cant take a mile off of material. just, you know, be gentle. some 220 or 240 grit paper will give you a nice smooth shape. just be shy, not aggressive. detonation is caused by hot spots, and anything that extends out beyond the general shape will heat up fast. the smoother the chamber, the more compression you can run without upping the octane. but the flip side of that coin is that you gotta be very MINIMAL!!! with removing material. because it in itself can lower compression. but then again, a C.C. is quite a bit, when you think about it. and lowering your squeeze by one cubic centimeter wont affect overall compression THAT much. still, dont get too crazy with taking out material. just a gentle bit of massaging on the sharp points. and HEY, as long as you have the guts ripped open, maybe massage the port throats just a tad. ive done a fair amount of port work over the years on different american iron heads. but i was never quite sure how best to handle the siamese exhausts on my brat engine. bigger is NOT always better. and sometimes SMOOTHER isnt better either. but in exhaust, smooth is usually better. the intake with a carburetor style engine usually likes a bit of texture for turbulence. keeps the fuel mixed up in the air better. Quote Link to comment Share on other sites More sharing options...
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