I completed two auto-rx treatments about 25,000 miles ago. Just for kicks I started my third treatment today. I used Castrol GTX 10w40 and plan to drive for about 3,000 miles before staring the rinse phase.
FYI, my last fill was a brew of Castrol Syntec 5w40 and 10w40. The removed filter had a few soft particles. Nothing major. Also, every filter since the previous RX treatments has shown the soft particles.
FYI, my last fill was a brew of Castrol Syntec 5w40 and 10w40. The removed filter had a few soft particles. Nothing major. Also, every filter since the previous RX treatments has shown the soft particles.