Hi all again!

I think I just stumpled upon a fact that'll kill my search for an early 2.5 GT(other than the Head Gasket debacle). Is what I'm hearing true? SoA says you HAVE to run 91 Octang, High Test?

Is THIS true??

Many thanks, Ted

Does the owner's manual say 91 or 89?

I've heard that before. That engine was tuned a bit differently. DOHC, etc. etc.

For 99 GT I usually used "plus" not premium. It depends on the station what octane that is because it blends reg and prem at pump so 89-90. Usually pinging was more related to how many miles were on the plugs not the octane in the tank.

i have a 97 2.5 gt dohc in basically perfect condition and totally up to date on maintance ( i am a tech for a living). even though i try not to, i ahve ran regular grade fuel without a problem. i have a few performance upgrades so i always try to run premium fuel or mid grade if i have to. all you can do is try regular gas, if it pings try a better grade fuel. the owners manual should clarify what grade gas is recommend.

Not trying to hijack this post but I am currently trying to find out why my 2000 Legacy GT pings (has from day 1) if I use the recommended 89 octane. Any thoughts?? My post is 89 octane "ping" but I will check back here for your collective wisdom.

I find it hard to believe that the pre-2000 Legacy 2.5GT would need premium (don't know if the 2000+ models are any different, though). They have the same engine as the 1998 Impreza 2.5RS (the only DOHC 2.5RS) and that car only requires 87 octane.

97-99 (some 99) GT = DOHC = Should use Premium gas and Platinum spark plugs - I always ran 92 in my 99 GT - check the owners manual for confirmation...

 

SOHC - not necessary.

 

Jamie