Who uses 89 octane gasoline?

[justwannano]

I do.
89 is 10 cents a gallon cheaper than 87 here in Iowa.

[Mudshark]

My old car (86 Chevrolet Caprice) recommended 89 octane, as does my new car (96 Chrysler LHS).

[Garfield226]

@justwannano

I do.
89 is 10 cents a gallon cheaper than 87 here in Iowa.

I just filled up with 89 at a Casey’s in southern Illinois. It’s 10% ethanol and was 5 cents/gallon cheaper than the 87 they sell.

[Stranger_On_A_Train]

@bouv

Hmm…these posts have me wondering if I should not use 87 octane in my car. I will make sure to read the manual, but just to see if any dopers know off the tops of their heads, it’s a '98 Subaru Legacy GT, 2.5 L engine. Since it’s the sportier version of the car, I wonder if it requirse a higher octane…that, and the check engine light is almost always on (it sometimes goes off after I fill up for a while)

You only need to use 87 octane fuel in this car. They didn’t start offering the Legacy with a turbocharger (in the US) until the 2005 model year; prior to that, it is naturally aspirated with standard (9.7:1) compression ratio, requiring standard fuel. (BTW, the difference between the GT and the other Legacy models is in the trim, the suspension, and the wheels. The engine is the same 2.5L SOHC with 165bhp and 166 ft-lb of torque for the 2000-2004 model years, all models inclusive.)

@bouv

and the engine sounds…off. Not bad, mayube not a ping, just off. My neighbor thinks it’s the head gasket. Having almost zero knowledge of an engine, and not a lot of time/money to get it looked at, I’ll assume it’s not serious.

Could be a leaky headgasket…or carbon buildup, or a blocked fuel filter, or worn plugs, or a faulty 0[sub]2[/sub] sensor, or any number of other things for which the effects range from minor to highly detrimental. You should have it looked at, soonest, before any damage propagates. Most of these things are not terribly expensive to fix (and from what I’ve seen, Subaru dealer garages tend to be quite resonable about cost, unlike some other manufacturers I could coughAudicoughMercedescoughVolkswagoncough name).

Stranger