Greetings,

I have a 2005 Ultra with 59K. I run full synthetic. I need an oil change. Riding season in Ohio is about to end for me in about 4-6 weeks for this season. Is it a safe practice to drain the synthetic, use a conventional 20w50 for the rest of the season before she sits for a long winter nap, then change it out in the spring and go back to a full synthetic?

Thanks for the help

 

It won't hurt a thing. Today oils are so good, there's little difference between conventional and synthetic unless you're running a high end synthetic like Amsoil or Redline. A very good conventional oil to use is Valvoline VR-1 Racing 20w-50. The used oil analysis reports for that oil return results better than most synthetics and it's available practically everywhere for around $5 a qt.

 

Synthetic oil is just thinner, so it'll cool faster.

 

There's a lot more to it than that, friend. Different levels of refinement of the base stocks, different types of base stocks, different additives such as moly, zinc, phosphorus, etc., different levels of those additives, different flash points, different resistance to evaporative loss and on and on...but a 50w is still a 50w.
Running a synthetic will allow longer drain intervals and to a lesser degree, depending on which synthetic vs which conventional, will provide for less internal friction, causing lower temps. Switching to a good conventional for the winter and then going back to a synthetic in spring won't hurt a thing. The engine will never know. In fact, I'd say it's good idea. Fresh oil is always a good thing in my book.

 

Why not just take the current oil to the end of your riding season, then change to whatever you want, and have the bike sit with new oil over the winter? This way in the spring you have one less chore to do, to get ready to ride.,,