The recommended alternative is 15w40 diesel oil, 10w30 is too thin. I'd ride it as is until I could find either 20w50 or 15w40, it can't be that hard to find one or the other

 

10W30 is too thin for these air cooled motors........particularly as the weather warms up around the country.

 

Harley themselves recommend a 10W40 motor oil if the lowest ambient temperature is below 40F, but most people never go with that recommendation and run a 'heavier' fluid year around.

Just pick up some Mobil 1 15W50 oil, which is only about $4.25 a quart and every bit as good as the high dollar "V-Twin" specific fluids.

Or run down to your local gas station and pick up some Castrol GTX 20W50... It's low cost and will work fine.

 

Any oil is better than no oil. I would use 10w-30 for a top off, if it was all that I had. However, if I had a store to go to, I would get any 5/10/15/20w-50 or straight 50, preferrably a diesel rated oil, and top it off and not worry about it. I'd ride it that way till it needs changed.

 

almost every auto store here carries 20-50 and all the motorcycle dealers and Indy shop..
Ur telling us that a town the size of Columbus, Ohio has Zero stores that carry it...

I'm thinking,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, NOT......

 

Thats what I was saying went to auto zone wal mart advance , no 20 w 50 WTF! On top of that the dealer I had do the last oil changed used royal purple thats when I was in Dayton, No bike shop here in the Columbus uses it , only use harley synthethic.

Whats the difference in the royal purple high performance oils vs the royal purple max cycle?

 

No 20w-50 of any kind in those 3 stores is almost hard to believe.......Heck, I just got back Autozone, where I purchase Valvoline V-Twin 20w-50.

 

I use Castrol 20W50. I get it at Autozone or Advanced. NAPA has it too. Autozones all over Columbus. Surely they have it. Better to be safe than sorry.