May 11, 2009 / 10W40 motor oil in hydraulics? #11 J_J Super Star Member Joined Sep 6, 2003 Messages 18,952 Location JACKSONVILLE, FL Tractor Power-Trac 1445, KUBOTA B-9200HST I was told to use Mobile-One 10W-30 in my Dixie Choppers. Seems to run fine.