Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance How long does synthetic oil last?

So was that at an interval of 7500K then? If so, are you saying you could've went another 12.5K then? Did you run Mobil 1 in your car from the time it was new? We had a 96 Geo Prizm for 5 years, bought it new, and I ran regular oil in it until it hit about 50K and then added Mobil 1 w/o any problems and I left it in there for some time, let me tell you. In an unrelated note, that was a great car, the only thing that went bad on it in 5 years and 95K was the battery and altnerator. We tuned it up at 40K and I did filter and gasket changes on the tranny at 30K and 60K, then had the entire tranny flushed at 80K with this T-tech machine. I'm sure its a great car for whomever owns it right now