I know this is a bit off topic, but I use Mobil 1 Turbo Diesel Truck 5w40 in my JD tractor with Kawasaki engine. It works perfectly and UOA are stellar. Plenty of ZDDP and shear stability for air cooled operation. It called for conventional 10w30 oil, however, it was not able to maintain oil pressure on hot days with conventional oil.
As I have posted here before, here in South Florida, my hard working air cooled engines require good oil. I actually had 2 Honda water pump engines fail due to oil related issues. Also, MANY generator operators had engines fail due to oil related issues. Air cooled engines are tough on oil here in Florida. Especially when run 24/7.
I have switched to Mobil 1 15w50 in my pumps and generators with perfect results. I have persuaded some RV guys that were having probs with conventional oils to use the syn with good results.