I can get Amsoil Signature Series 0W30 and Pennzoil Ultra Platinum 5W30 for the exact same price of $7.50 per quart shipped to my door. Running Mobil 1 5W30 now, but have run Amsoil Signature Series 0W30 in the past. I haven't had any experience with Ultra Platinum as of yet. I am waiting for my engine to break in more and to stop consuming oil before I make the switch. Which one would you go with at the same price point?