Originally Posted By: PT1
Harley doesn't seem to publish much in the way of API specs on anything except the mention of CF-4, CG-4, CH-4, CI-4 in my 2006 Dyna owners manual. The viscosities listed are 10w40 for below 40*F, 20w50 for above 40*F, 50w for above 60*F and 60w for above 80*F.
This...