It's hard to prove anyone is getting more bang for the buck. Sure you can pay more, but alot of guys are still in the mindset of changing oil every 3k miles. Harley sells alot of oil marketed with their name on it, it's easy to get and alot of people feel its a safe bet if any warranty issues come up.I haven't heard of any motor failures with Harley oil, and I think nobody else could find their oil's to have caused any.And there are alot of 20/50's around like Amsoil, mobil 1 v twin, Castrol,Valvoline, Redline, royal purple, Brad Penn. Those oils are mostly synthetic and work fine. Like car oils, the more you read about them the more it seems any of them will keep your vehicle around a long time. It boils down to price and availability. They all claim to be the best, and try to make you feel unless your paying top dollar for oil your not taking proper care of your vehicle.So if you ride your bike 4k miles a year, you may not really need $12 a qt oil, no matter who makes it.,,