It seems to me that most people at this site consider Chevron Supreme, Pennzoil, and Castrol to be the best conventional motor oils (based on VOAs and UOAs of oils that have been tested). So which of these three motor oils stands above the rest in terms of quality for conventional motor oils? I assume that Castrol maybe would lose points because its pour point apparently is not as good. If that is the case, then which motor oil stands as the best-Pennzoil or Chevron? Or is the difference between conventional motor oils so slight (with maybe a few exceptions of very poor qualioty motor oils) that it really does not matter which a person used?