[Kenneth_Moore]

I've used synthetic oil (Mobil 1 V-Twin lately, Mobil 1 previously) in my HD engine for quite some time, but the only reason I do is because it's so hot here in South Florida. The synthetic drops the engine temp from almost 250 to below 200 in the summer. If it weren't for that, I'd run a quality mineral oil. I change the oil in my HD about every 1.5k miles; it gets really dirty really fast, so the synthetic gets expensive. For filters, I use HD. Trans and primary case, regular (non-synthetic) HD gear and primary case lubes.

BTW: I haven't heard anything good about HD's Syn3 from anybody whose opinion I respect. The best I've heard about it is that it's ok for the primary. None of the mechanics I know at the local dealerships run it in their bikes.

 

[Kenneth_Moore]

...that you had to change oil in a Shovelhead. The burn/leak rate on mine meant that you went through 3 quarts every 1500 miles. Of course I had to change the filter frequently because of all the metal shavings and chunks that would clog it up regularly.

The burn rate means I go through 3 sets of sparking plugs every 1500 miles. The HD-1 drop in filter only catches items the size of AirHawk's kidney stones or larger...