People get stuck on miles for OCIs, really should be using engine hours instead. If you drive it everyday, all highway, putting on a good number of miles, 200 hours is the MAX you should run the engine oil. Any other conditions, mixed city/hwy, lots of idle, towing whatever, go to 100 hours. Best way to test of course is get a bulk set of Blackstone containers (10% discount I think), and send the oil off for testing.