Own a 2004 3.3L Highland. Have 300,000 miles. Changed oil anywhere from 5,000-15,000 with every different flavor of 0w30 or 5w30. At 290,000 both valve covers were leaking, cracked air intake box, and the vehicle is not cleaned very often. Changed the VC gaskets, timing belt and spark plugs. Car still runs and expecting to get another 100,000k on it. Original motors and original transmission. This SUV is something else.