Lord of ScoobyMods, ,
19' Impreza Sport 5 dr / 01' Forester S / 13' OB CVT / 10' Legacy 3.6R / 99 Mita MX-5
It's not hard to change at all really. As for when, that really depends on where you drive. Out here a lot of people live on dirt roads and would never make the 30K interval. It's easy to check and see. I usually look at it every spring.