Hello. My Girlfriends car isnt driven very much, maybe a few hundred miles a month if that. Her father insists that she still change her oil every 3 months. I know there is no harm in doing that, but is it really called for? When I check the oil, it is still a light color. What oil change interval would you reccomend for someone that puts on low miles every month. She drives a 1998 Toyota Camry, and uses regular 10W30 oil. Majority of those miles are city miles. Hope that is enough info. Thank you very much in advance.