['97ventureowner]

The oil change indicator is fairly accurate. The oil life is figured using on a couple of factors, the temperature of the engine and engine revolutions. It is primarily based on driving conditions and not mileage, hence the length of time between changes can vary from one oil change to the next. I know GM recommends that you change it within 600 miles once it indicates it needs changing. With today's quality oils , I don't believe much damage would be done by going over the time, but don't wait too long or make a habit out of doing so. I think in the future you will see more attention paid to 5000 mile oil changes as a result of improvements in both engine design and oils. Also stretching the change frequency can save oil in the long run. It is not an indication of a "no oil" situation in the engine, rather the additives and protectants in the oil are being used up. My only problem with these systems is that if you use synthetic oil, the oil life system does not recognize it and you'll see the same results for change frequency as you would conventional oil, even though you can go longer distances between synthetic changes. One thing to remember if you change your own oil, or have a garage do it, is to make sure the system is "reset" after the oil change for it to work properly.