Pennzoil sucks so bad i could develop an oil right now that is better than it. I know a friend who used their conventional oil twice. During the second run with it he noticed something terribly wrong with the engine. He is also mechanic so he took the engine apart and was shocked to see all of the wax build up in the intake and valves and pistons. We both tell people NEVER to use Pennzoil, its not a suprise I rarely hear anything good about Pennzoil, I hear that the new Platinum is pretty bad too.
