Doesn't it have an oil life monitor? That 8,000 mi. sounds realistic (on the high end) but it should have a monitor that, if reset when the oil is changed, will show a message on the dash when it wants the oil changed. If you prefer to change at a set mileage (as I do) 7,500 mi. should be a good interval unless it sees primarily short trip, stop-and-go driving, in which case 5K is more than adequate. A Mopar brand filter will best preserve your warranty should it need any engine work, but I trust Wix and there are other good brands, as well.