I FINALLY decided to spend a bit more money & switch over to synthetic (Mobil-1) after 2 years and 55951 miles later. Damn! What was I missing out on?! The engine runs so much smoother and quieter (as if I had done a tune-up). I'm never going to switch back to regular oil. Anyway, I decided to use 5w30. Is this the recommended oil?

 

If you look in the owners manual, you will see that 5w30 is the recommended oil for all temperatures. 10w30 is okay for areas where it doesn't get below freezing.

 

Does 10w30 provide more high temperature protection than 5w30? Why would someone pick 5w30 over 10w30 if he/she lived in a place that never gets below freezing (and never drives his/her car to go skiing)? I tried reading that "Everything you ever wanted to know about motor oil" website once, but it's a bit confusing.