What grade of oil is specified for our CL-S? I'm in AZ, but not sure if that should matter.

 

I used 20/50 out there....10/40 in the winter.

 

5w-40 should be good in that region. Make sure its synthetic grade. This is what i use in south TX and Laredo normally averages on a daily basis in the summer about 98 to 101.

 

5w-20 Haven't you read the manual?

 

The manual says 5-20 but 5-30 is also good and will cause no problems at all. Personally, I use Mobil 1 5-30, although any good brand of oil will do just fine. If you use dino instead of synthetic, just change it more often. ALWAYS use a good filter - don't skimp here.

 

5w-20 was put in the engine to help Acura get Lower emission and better MPG. Nothing to do with protection. That oil grade is to thin for the southern region of USA, speciallly Arizona.