- Mar 1, 2007
- Pacific Northwest
I have a Mercedes SL with V8 that sees little use and then only in the summer. Typically less than 1,000 miles a year of mixed city/highway but almost always involving several hours of operation each time. I have habitually changed oil every year and always asked myself why because the old oil coming out looks spotless, just like the new oil going in. Mobil 1 15w50 is the oil with Mann OEM filters. Last time I changed with M1 15w50 EP. Has anyone studied how often a very good quality oil will last in low-use applications? It seems a shame to change on a calendar basis and throw away oil that is still perfectly good. The car has absolutely no mechanical issues that would degrade the oil, and M1 EP is billed to be a very long-life product. Heavy equipment is serviced on the basis of hours of use. Is is reasonable to base my oil changes on a mileage schedule? Cost is not the issue, I just hate to waste things. Thanks in advance for your advice.