Originally Posted by Uncle Scotty
ya know...after the first couple thousand miles on the 0w40 when my engine was a bit LOUD....it has subsided and is pretty quiet now....but im going to a more robust oil for summer
and since THERE IS NO REASON AT ALL ON THIS PLANET to use ANY 5w30 oil ever made.....
i will continue to say that anybody who puts ANY 5w30 oil in these cars is an idiot
As always I assume you're speaking in the context of a turbo EJ, but even there I have to disagree, there are certain 5w30 oils which have excellent performance characteristics for a turbo EJ. Redline 5w30 stands up to track days as well or better than RT6 and is substantially better in the bitter cold. A smoking value it's not, but from a technical perspective it's about the best oil available for a turbo EJ.
The old SM formula of Valvoline MaxLife Synthetic 5w30 was nearly indistinguishable from German Castrol at everything but extreme cold performance and was a great value. Spec sheet, VOA and UOA info on the M1 ESP 5w30 I just put in my car indicate it's one of the best oils available, with a cutting edge additive package and excellent base stocks. It's the development platform on which the latest (SN) generation of M1 0w40 is built, see this
presentation, particularly pages 31-32. The only area it might be a bit weak is drain interval, but that's still TBD.