I have run HD synthetic from almost day one, I have tried others but the bike seems to run a little cooler with this oil. I have always had a good PM schedule for the bike and I always take off the front lower fairing when the temp reaches 100 degrees, just not enough air on the motor when in traffic. Some of the parts replaced are, oil pump, drive belt, oil pressure gage, cam tensioner and speed sensor, clutch and throttle cable. I don't consider this to be major repairs just normal wear and tear. The engine has never been apart and burns no oil and still has good compression. I don't do anything extra special, I just stay on top of the maintenance and don't ride it hard just long.