those of u that use 98grade fuel do u find that there are any MPG and or performance advantages from this grade of fuel with a Subaru engine???

 

I currently use 95grade and need 15litres/100km which seems low???

I tracked my MPG when I first got my 2000 Outback and I did not see any difference between 89 and 93 octane gas. I now just run 89 octane because there was no gian for paying the .20 cents more a gallon.

Regular grade actually has a bit more energy in it per gallon. The difference is slight but it is the regular grade that would favor higher economy. You can always perform a personal real world check and see what results you see. Even a slight improvement with higher grade would not offset the higher cost per gallon. I would run the lowest grade where the motor ran good.