Lucas Semi-Synthetic SAE 10W-40 ATV Engine Oil is a long lasting oil that stands up to the high temperatures of slow moving hard-working air cooled engines. It exceeds manufacturer specifications and meets JASO specifications.
API SL Certified, Lucas Synthetic SAE 50W MC Oil is specially formulated with the finest base oils and exclusive Lucas high performance additives for all 4-stroke air cooled V-Twin / Opposed Twin / Slant Twin engines made after 1984.
Your oil performs better than anything else
I've used many different types of oil, including synthetics, in my 1979 Yamaha XS650. Last fall I installed Lucas High Performance 20W-50 motorcycle oil. There was an immediate improvement in shifting, but there always is after an oil change, and over time the shift quality degrades. I also wanted to wait and see how Lucas Oil holds up in hot weather, as these bikes are notorious for difficulty in finding neutral when stopped. Well, I haven't been disappointed. Your oil performs better than anything else, shifting and engine performance are still so good I'm amazed every ride.