My car is 1/2 year old today. Or tomorrow depending on which way you round 1/2 of 365. I have 1679 miles, my longest drive being no more than about 70 miles round trip and those very few thanks to jury duty. I anticipate about 3k miles at the one year mark. So, with most trips being 3-5 miles round trip, should I change at 1 year ~3k miles or is it safe to go about 5k mile intervals every 18 months? Or?