brucew44guns
Silver Member
- Joined
- Jul 23, 2010
- Messages
- 181
- Tractor
- John Deere 630
10W/40 oil has been obsolete in Ford engines since 1989 I believe. I think I remember that some Ford manuals warned of voiding the warranty if 10-40 was used. Usually, 10W30 is a better choice, more sheer stable. If you need 40 grade protection in that tractor, I would use a 15W/40 HD diesel oil like Delvac, Rotella, or Chevron Delo, and forget automotive 10W/40. If a delivery truck had 500 cases of oil onboard to deliver to places, it may not have even one case of 10W/40 in the load. I have not sold one case in 15 years.