Postby smj999smj » Mon Mar 05, 2012 9:29 pm
API certified 5W30. If you replace your oil at 3-4000 mile intervals, conventional oil will work just fine. If you operate your vehicle for extended intervals or under "severe duty" type conditions, then synthetic oil is the way to go. Difference in brands are usually defined in additive packages and individual preference. Which brand you use is not nearly as important as whether is is API certified or not, which all "major" brands are (ie Castrol. Pennzoil, Mobil). If you insist on synthetic, Walmart Syntech full synthetic is made by Royal Shell, who also makes Shell Rotella (a quality oil used by many heavy duty truck drivers and mechanics) and it's much cheaper than Mobil One and other "name brand" synthetics.