hey guys I'm about to do my first oil change and i was just wondering if mobile 1 is ok to use or if i should go with royal purple, the car is stock with intakes and turbo back exhaust and is only used on the street, also i read the fluid sticky and i seen one post that said 5.3 ltrs and another with 4.7 ltrs of oil is 5.3 only if you have an oil cooler thanks in advance