Has anybody tried this oil? According to the specifications, it more than meets Harley Specifications. With a TBN of 12, it should hold up better than Syn 3 or HD 360.
I saw it at Tractor Supply and did some research on it.
MYSTIK® JT-8® SUPER HEAVY DUTY ENGINE
SAE Grade 15W-50
Gravity, ASTM D 4052
at 60°F 28.1
Pounds/Gallon at 60°F 7.
Specific Gravity at 60°F0.887
Viscosity at 100°C, cSt 20.0
Viscosity at 40°C, cSt 168
Viscosity Index 138
CCS Viscosity, cP,at Temperature 6600
Pour Point, °F (°C) -17 (-27)
Flash Point, COC, °F (°C) 430 (224)
Noack Evaporative, ASTM D 5800, % Loss 12
Total Base Number, ASTM D 2896 12
API SERVICE CLASSIFICATION CATEGORIES
Allison C-4
Caterpillar*
Cummins CES 20078
Cummins CES 20076, 20071
Detroit Diesel 93K214**
Deutz
Ford M2C171
General Motors 6094M, 6.2L,6.5L
CI-4 Plus, SL, SJ, SH

Sounds like diesel engine oil.
Ted