I use mobil 1 - 10W30 ... in my rsx and my bike (2003 yamaha R1) Abike magazine did a comparison on different oils ... i dont remember exactly which ones but i remember that mobil 1 was superior to all except like 2 others and they tesed like 12 different oils. car and bike oils. the said not to let color oils fool you that they break down just as fast (royal Purple)