Originally Posted by esfourteen

correct, the 10w40 was for summer temps with a twin turbo car. I originally ran 5w30 at my first oil change to sythentic. As for the weight of this additive, its a very small amount going in.

I will be giving the ester oil a try as well, I did consider it but my valvetrain chatter seems to be quite unique. Plenty of people (including myself before the build) ran other oil with no noise issues. I suspect that my VVEL did not like the engine break in oils used.