Got my dream bike (Rocket III) and my loyal Bonnie took second booking this summer. With only a thousand miles on her total for this season and running a full synthetic oil....should I change it out before putting it up for the winter (Oct - May in Alaska) - or is it okay to leave sit. The oil is dark so I'm leaning toward changing it - but man - at $53.00/gal. for Mobil 1 I'm thinking not. No detergents to break down right - or will the carbon in the oil eat away at seals, etc. To change or not to change? What would you do?