Evening, I have to refill with my Seat Oil. I have bought 1L oil from Castrol now. I know anyway that with my Seat the oil 5W30 (Longlife) with the specification 50400 is in it. However, I do not know of which brand this is. Do I have to keep in mind something else? To be honest, I have never done that before, and I am afraid to harm the engine. What can you do wrong with oil and refill? Seat Leon 5f 1.4TSI engine with 122ps