Thanks for the heads up. I just got off the phone with a Valvoline tech. who said the racing oil was better than conventional oil in every way- "had a far superior additive package and not to be concerned at all". Also, no problem with 50 wt. oil if temperatures are above 80 degrees. It has to be better than Castrol(if it is made in England)- they can't make a decent car, how can they make oil?