Harley Davidson recommends it (Citco I think)but No!!! Just use the correct weight for your motor, time of year and how you ride it!
Sunoco, makes Harley Davidson engine oil
20w50 is recommended in temperate zones. If you live in an area where the temperature does not dip below 75 degrees Fahrenheit, you can use regular 50. Clarification: If you live in an area that has...
Knowing the year would help answer this better.
we use 20/50 of any brand you choose.