Originally Posted by Peaty
I've had this for a while but I believe the reasoning is still valid.
This may be true up until 2010, in the 2010 service schedule says all legacy's and outback's are 60k for the plugs. The impreza and forester are still 30k for non-turbo engines.
The 2009 service schedule says:
Spark Plugs 2.2L engine every 30K
Spark Plugs 2.5L engine every 30K
Spark Plugs, all Turbo 2.0/2.5 and
3.0/3.6L 6 cylinder engines every 60K
Here is the 2000-2009 Service Schedule:
Here is the 2010+ Service Schedule: