Did you check the level to see if you even need any more? My 08 calls for 38 on a drain and refill and 32oz fills is up to where the manual specifies.

 

Everything is going to blow up if you mix the oil, may even affect the space, time continuum...YD

 

I use my primary to get rid of my extra oils.Most of the time it’s all 20w50.I have mixed different brands and sometimes synthetic and semi synthetic oils.Lucas,valvaline and whatever else I used to change the engine oil with.Its all slippery.Ive never had an issue.

 

I think Yankee Dog was trying to tell you that yes, use the Mobil to top it off. I have done it before because guess what I forgot to put the plug in so I completed the change with M1. Do I hope I have not changed the world axis, no not really.

 

Bought my bike new so likely was full of Harley oil. I do all 3 holes each year with Mobil1 vtwin. Since primary is 45oz dry and 38oz wet, it was mixed at that point with something different. Betting most bikes have had a mix of some sort

 

Actually, not true, if you look at the part numbers for bikes pre-2017, it/they all are the same part number.....It is ALL the same oil, my 2013 103 and my 2011 96, used the same part number in all three holes... Harley just trying to make it hard.... Mix what you want it will work.... CSM-H