Apples and oranges I suppose but we had a 4020 Diesel on our farm for decades. It ran in Farmers Co-Op 15w40 for 30+ years, still running today but no longer farming. I agree that any 15w40 would be well suited to your application. Walmart 15w40 is affordable as is Tractor Supply Travelers brand.
P-3C and P-8A Maritime Weapons and Tactics Instructor, Instructor Tactical Coordinator and Mission Commander