^^^but it would rap out quicker, less resistance.
i never run 20/50, not even in the texas summers, over 100 for a good portion of the summer. you dont need it. i usually run 10/30-10/40 year round, never had any problems (knock on wood). if i were to do sustained high speed, i would at least consider it, but i know some people that race bimmers, and they run light oil, and have been for years on the same motor. we are also talking full blown race engines.
i think it really depends on your driving style, and the fact i dont care if i granade an engine, it will give me an excuse to build my stroker.
BMW--Because Mine Won
BMW--Built My Way-better than good