[meebs]

EJ25 is 10:1.
EJ20 is 8:1.

Is this true or false, higher compression engines like higher octane petrol.
But the EJ20 is going to like higher octane because you are ramming air into it?

Does the EJ20 retard timing if you put lower octane fuel in?

 

[Eby]

True, true, and true.

 

[Graham]

EJ25:

MY98- DOHC, 9.7:1

MY99-SOHC, 9.7:1

MY00, 01- SOHC, 10.0:1

EJ20: U.S. Spec WRX

MY02- DOHC, 8.5:1 Compression Ratio


I don't personally know of any engine that retards timing on a basis of octane, just don't use anything less than 93.

Graham

 

[LVSUBARU]

It will retard if the motor knocks.
The motor will knock if you use low octane fuel!