Maintenance: Subaru Periodic Vehicle Maintenance Services:

Spark Plugs:

Spark plugs have a 60 month or 60,000 mile replacement interval on most Subaru vehicles. There’s not much more to say about them. If you have the extra time, it never hurts to remove one or two spark plugs to see how the engine is running between replacement intervals. This will also give you some advance information on how well the spark plugs are wearing.

Also, unless you have the complete maintenance record for the vehicle, there’s no way to tell for certain whether the spark plugs were replaced at the recommended interval. Pull one out and take a look.

Spark timing and idle speed are preset and do not require periodic adjustment, as was necessary during conventional tune-ups on older vehicles. Once again, if you want to take some extra time or if you suspect a problem, it’s still possible to check the ignition timing and idle speed. If either is out of spec, they can be adjusted on most Subaru vehicles. Consult the appropriate vehicle service manual for additional information on timing and idle speed setting procedures and specifications.