And I noticed the difference immediately. Acceleration seemed smoother and my lifters are quieter. And since I'm a dealer, I get it for about $4.25/qt. That's not much more than Mobil 1 and it's much better. The wear statistics with Amsoil are unheard of. It beats Mobil 1 in almost every category. My cars like it...I like it...I won't change EVER.