I just finished changing my oil. Not too messy .
The oil used during my first oil change was Shell Rotella T. Rotella T provides the API certifications but does not, or is no JASO certified.
As I understand, the JASO certification is suppose to help the oil lubricate both engine and clutch.
I have been sensing that my clutch has been slightly slipping when it is initially engaged, so I decided to give the JASO oil a try.
I selected a synthetic blend by Castrol 10W40 Actevo 4T that I got at Walmart for less than $6/Qt. This is more expensive that the Shell Rotella T, but not that much.
After changing the oil I went for a short ride on a local twisty road, Harmony Grove. The engine at idle seemed quieter, and yes, the clutch doesn't slip like it used to. The other advantage is the engine feels stronger when "trying" to accelerate.
My initial impression is that the JASO synthetic blend oil is well worth the couple of extra $ for 1.7L of oil.
