Magnusson Moss Act

How Safe are Extended Oil Change Drain Intervals?: "It's Federal Law as dictated by the Magnusson Moss Act for the car manufacturer to void your warranty for using oil with longer drain intervals unless they provide both the oil and the labor to change it, free of charge, so the warranty is not at issue. If the motor oil is capable of protecting your car for longer, than your car does not benefit from changing it more often. You, who has to pay for the oil, certainly do not benefit from spending more money. Oil manufacturers are in business to turn a profit and any way they can they will. Their oil change recommendations are geared towards maximizing profits and keep you coming back as often as possible."