3 parts Rotella-T 15W-40 : 1 part Mobil-1 15W-50 synthetic. Smooth shifting, no clutch slippage, economical. Bill in Yardley, PA wkdenton at verizon.net '96 GPz1100 '86 SRX600 '81 VX920RH '80 CB-X '78 XS650E '77 XS650D '71XS-1B