Quote Originally Posted by Mellow Yellow View Post
I don't know....I put 5-30 in my 2005 3v shortly after I bought it and the cam phasers start to sound like they were coming out of the engine. There are a lot of plastic parts in there that may not be able to handle the pressure. Went back to 5-20 and everything settled down to "normal"
I have to agree with you on this - since I purchased my s550 three months ago I've done a lot if reading on oil - enough to turn me off ketchup and things of the like, but that's another story - in everything I read lead me to believe that 5w20 was probably the best choice for today's average engine - 0w20 seemed to be that next best but would break down sooner - I believe. API stands for minimum standards so I wouldn't go cheap and would stick to full synthetic. Saying all this it's not what I will be using lol because I don't think the coyote or anything pushing 350 HP or more and boosted are average grocery getter engines. When I change my oil I'm going to send sample out the see what was actually in there from the factory assuming the car has the original oil as it had 5ooo on it when I purchased it.