Pennzoil makes terrible motor oil. It causes wax build up, sludge, startup problems, flat tires, and just all car problems in general. DO NOT USE THIS OIL IN YOUR CARS. Instead, please send your unused Pennzoil to me. If you have 5w20 PP, it is more preferred.

There is a lot of good oil info on these forums, please edumacate yourselves:
http://www.bobistheoilguy.com/forums/