My Stinger is leased so the Mobil 1 5w30 the dealership puts in (for free twice a year!) is fine with me. They break it, they bought it. But on my Optima SX with 141k mostly city miles, I always used Amsoil and recently switched to Pennzoil Ultra Platinum 5w30. With all the conflicting opinions floating around Amsoil just seemed like the safest bet. But the
Project Farm video convinced me the Pennzoil is almost as good for half the cost.

Almost as good is good enough for my backup car. I'm more inclined to go by real data rather than "this is what muh daddy swears by" testimonials.