TRANE DEFENDER S4 20W-50 API CH-4/5+1L  

“Semi-synthetic engine oil for heavy-duty diesel engines
API CH-4/SJ (approved by the Department of Energy Business), CG-4, CF-4, SJ, ACEA E3, MB 228.1, MAN 3275, Caterpillar ECF-1-a
Helps protect the engine from wear and tear
Helps extend the life of the engine
Keeps the engine clean and operating at peak performance
Suitable for heavy-duty diesel engines.”