View Poll Results: Which is better for an aluminum engine
Voters: 55. You may not vote on this poll
Pennzoil vs. Mobile 1
#4
I'm really not sure what to believe.
#9
royal purple is junk.. leaves a residue (purple one at that) on all your parts.. I know many shops and shop owners, none of them use it (they sell it.. sure..) but they wont touch the stuff for their cars.
#13
If you're going to choose between the two oils above go with pennzoil. It is not any better or any worse than mobil1. It is often cheaper by at least a dollar a quart. If you want a true synthetic runs Amsoil. Mobil 1 and Pennzoil are group three's mixed with group 4. Amsoil is a group 4.