My dealer put 5W20 in my 12's first oil change, I argued with them but they refused to change it back to 5W30 so I had to do that myself.Dealer has apparently been using 5W20 in my '12. Just realized that today. When spring comes I'm going to start doing it myself from now on with 5W30. The 20 weight stuff is like water at full temp.
The first number indicates the weight when cold with a lower number being thinner which would flow easier. The second number is the weight when at operating temp.The cap on the Oil fill states 5w-20 on my 2009. I am not mechanically inclined so explain it to me like I am 5, but is there a real difference between the two?