Originally Posted by Davey

I don't think I've seen it on any 2011's either.

I forget where I read it but IIRC there was a revision to the ECU programming that no longer requires ester oil on the 2011.

I thought I also read that the ester was at first recommended because of valve noise, which could have been interpreted as knock.

If that is true, that would cause the car to pull timing and would definitely get better after an ECU reset (and come back.)