Hello people I just bought a new zero turn with a 23 up Kawasaki engine.. & was wondering about what oil to us in it...NOW..I have read the manual..but my BEEF IS i have 2 ride on mowers twin cylinders.. that I have used 5 W 30 CASTROL OIL.IN THEM BOTH..with well over 1300 hrs on them no issues at all..the coldest in the spring would be 10© to the hottest 75 © in the summer ..anybody out their using different oils other than what is specified.??