The car is a 96 Lincoln Mark VIII, it has seen Motorcraft 5w-20 and 5w30 from the dealership until I bought the car at 50,000 miles and subjected it to nothing but Mobil 1 5w30 for almost 40,000 miles. The car is about to hit 90,000 miles and I switched it to Amsoil 10w30 XL. It doesn't burn any oil between my 5000 mile oil changes (knock on wood). The car seems more responsive now with the Amsoil but it's probably a placebo effect after changing the oil. I'm gonna send in this Mobil 1 sample I took when draining the oil to Blackstone, a little bit nervous considering this is my first UOA.
