no i'm not asking what oil you use. don't care if you don't like what i'm about to ask. do you think there is an actual dam bit of difference between royal purple 20w50 max cycle synthetic motorcycle oil at $12.50 a quart and their multigrade 20w50 synthetic at $7.80 a quart. sounds like marketing doing a good job of making you feel like you should pay more.

 

Possibly! Harley recommend a diesel spec oil for their engines, which is higher duty than ordinary auto oils, so that may be where the difference is. Check the bottles to see if they quote different spec numbers. You may find the specs in your owners manual.