As a new Subaru owner I filled my WRX up with unleaded standard petrol. Should I be using a higher quality unleaded like Optimax?

Does it really matter?

 

I guess yours is a UK spec in which case 95 RON is fine but to get the most out of it super unleaded would be better imo .
My mate has a 2001 WRX (UK)and he's found that when the spark plugs need changing on 95 ron it would sometimes cause the cel to come on.

 

Just noticed today that my petrol cap has a sticker that says to use RON98 unleaded. So decided to fill with 97RON super unleaded.

My WRX definitely seems to be running better. So much that my wife noticed - she said my gear changing was smoother!

Not sure if it's our imagination though!

Think I'll pay a bit more and continue with premium.

Any Thoughts?

 

If it says use 98 then use 98. Currently in the UK that means either Tesco 99 or Shell V-Power.

 

Do what he says and you wont go wrong