From the “If all else fails then read the directions” file: My 2001 Road King will sump and puke when riding highway speeds when hot. And this summer has been super hot in Texas. I have convinced myself the puking is caused from the oil overheating thus losing its viscosity, and the pump can’t effectively return it to the reservoir so it pukes from the breather. When not hot, or not at highway speed, it does not use a drop of oil, even with the reservoir grossly overfilled. Both my RK and old Sportster manuals clearly specify SAE60 for ambient temps over 80F. I currently run 20W50 Dino and will change it soon, then after a few high-speed puke tests will add a crash-bar oil cooler. Only want to change one thing at a time for testing purposes. Anyone here run SAE60 summer oil? Got any feedback?