See also:

Fuel
Use of a fuel which is low in quality or use of an inappropriate fuel additive may cause engine damage. ...

Air cleaner element
WARNING Do not operate the engine with the air cleaner element removed. The air cleaner element not only filters intake air but also stops flames if the engine backfires. If the air cleaner eleme ...

The Inside
The interior is quiet enough at idle that one time I didn't even realize it was running. That's when I recognized Subaru finally seems to have licked this engine's chronic idle vibration. In this ...