Trojan Boat Forum

I have a 1989 International with the original MCCK generator and am curious what type of oil I should use in it? I replaced the oil once with Onan oil which was fairly expensive and was hoping I could switch to something else which would be of equal value

For temperatures from 30-100 use straight 30 wt. For temperatures from 60-100 use straight 40 wt. For temperatures from 80-100 use straight 50 wt. For temperatures from 20-100 use 20W-40 or 20W-50. For temperatures from 0-80 use 10W-30 or 10W-40.