Actually the "oil service" light doesn't "turn red" base on mileage intervals. The onboard computer will determine the oil change interval base on many factors.......% city/hwy driving, your driving style, upshifts, downshifts, etc. fuel/air mixture, etc.
However, many drivers don't pay attention to this "oil service light" and will change their oil/filter on their own preference and then reset the "oil service indicator".
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