best oil viscosity rating for 1200 sportster
 

what viscosity should I use, mainly short trips in town

What does your Owners Manual say to use?

Yes, refer to the owners manual.

Odds are it's 20w50, but depending on the temps where you live, the "right oil" can be anything from 10w40 to straight SAE60 and everything in between.

Welcome from Hampton Roads Virginia. Since it's 60 degrees up there this morning and close to fall, I would probably go 10w40. Maybe next summer, 20W-50.

But truly either would work. Depend on your riding season, if you change it only yearly, I would just go 20W-50 or just use the car Mobile 1 15W-50. What I use and it's fine. I have started mine as low as 35. (Not anymore..too old for that silliness but I have almost 50K and it still runs like new.)