Welcome to AF ! I too run synthetic in my '06 Uplander ( still under warranty.) and keep it in my engine for roughly 12,000 miles. I do however change the filter halfway through the mileage period as that is an important piece of your engine lubrication system. Changing the filter allows the new filter to continue to trap more contaminants while keeping the oil in your engine "fresh". The oil still looks good after the filter change, a sign that the filter is doing it's job. Also make sure if you decide to go this route, you top off the oil in your engine to compensate for any that is lost during the filter changing process.
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Thought for the Day… Alcohol does not make you fat - It makes you lean... against tables, chairs, floors, walls and ugly people.
If a prostitute here in America loses her job to a prostitute in India , is that considered "outwhoring"??-Jay Leno