Time for an oil change on my 08 Ultra. Been using Mobil 1 in Crank Case and Primary. I have several quarts of Amsoil I would like to use up - Any problems using the Amsoil in the Primary and Mobile 1 in the Crank Case? Both are 20/50.

 

I try to avoid synthetics in the primary because my clutch acts funny with them but you will get all sorts of opinions on this. For me, the best primary fluid I have used is the HD Formula+ but again, that's my opinion...

 

I also avoid synthetics for the Primary also! HD formula + or Spectro Chaincase oil for me!

 

You can use it in the primary however I use rotella t 15w-40. It's cheaper and I've never had a clutch issue on any bike I've used it in.
The primary needs a fluid that has the JASO MA spec listed on the back of the bottle. Amsoil v-twin and mobil 1 v-twin both have that spec listed,so yes u you can use them,mix them,whatever.
It's not going to cause any issues no matter what anyone here says

 

Can you use mobil 1 v-twin in all three holes?

 

20w-50w syn in the engine
70-140 in the tranny
either ATF-F or Rotella 10-40 in the primary

I would not use syn in the primary and if you are not comfy with ATF, Rotella is the best choice!!

 

Yes, I've been using Amsoil 20-50 in the primary for about 20K miles.