Oil Change twice yearly? With Low Mileage

[JFP in PA]

One major flaw in the argument: We run Castrol Syntec 10W-40 oil in our customer’s cars, and collect UOA’s to determine the correct change interval. The exact same oil in one car had a TBN of 6 after 8,000 miles; another had a TBN of 3 after 5,000 miles……….. How the car is driven matters (and varies) more than most think, and can significantly shorten the oil’s expected life; so basing your oil change interval on someone else’s UOA is wishful thinking at best. If you do not have data on your car, change the oil more frequently, no more than 5-6 K miles…….………