Sparex source: https://us.sparex.com/15w-40-heavy-duty-diesel-engine-oil-2-5-gallons-128963.html Product: 15w-40 Heavy Duty Diesel Engine Oil - 2.5 Gallons - Sparex S.128963 SKU: S.128963 Listing note: API Service Rating CK-4, Great wear protection for long engine life. Order in multiples of 2 (priced each) Detail enrichment pending: OEM cross references, fitment, catalog pages, and full specifications.