Procurement brief
Commercial fit and product signals
Ultra1Plus SAE 15W-50 Conventional Heavy-Duty Diesel Motor Oil API CK-4/SN is listed for Diesel engines, Fleet maintenance, and Heavy equipment service. The verified catalog signals on this page include SAE 15W-50 and API CK-4/SN. MAXILUB uses those details as the starting point for product-fit, quantity and package discussions; they do not replace the equipment manufacturer's current requirement.
Current product data sheet
Documented formulation and performance
PDS revised 04/25/2025
U1P-DUTY SAE 15W-50 Heavy Duty 4 Motor Oil, API CK-4/SN is formulated with conventional base oil and a premium additive package. This oil is designed for use in for use in high-speed four-stroke cycle diesel engines designed to meet 2020 model year on-highway and Tier 4 non-road exhaust emission standards as well as for previous model year diesel engines. This oil is especially effective at sustaining emission control system durability where particulate filters and other advanced after treatment systems are used. U1P-DUTY SAE 15W-50 Heavy Duty 4 Motor Oil, API CK-4/SN provides enhanced protection against oil oxidation, viscosity loss due to shear, and oil aeration as well as protection against catalyst poisoning, particulate filter blocking, engine wear, piston deposits, degradation of low-and high-temperature properties, and soot-related viscosity increase. In addition to API CK-4, this oil exceeds the performance criteria of CJ-4, CI-4 with CI-4 PLUS, CI-4, and CH-4 and can effectively lubricate engines calling for those API Service Categories. When using this product in conjunction with fuel containing higher than 15 ppm of sulfur, consult the engine manufacturer for service interval recommendations.
Documented benefits
- Conventional diesel and gasoline motor oil helps reduce wear and increases engine protection
- Strong shear stability provides stay-in-grade performance
- Conventional motor oil minimizes oil consumption in all types of driving conditions
- Enhanced oxidation control
- Ultra1PlusTM is designed to maintain its viscosity while protecting the engine against thermal breakdown at high temperatures
Typical properties from the PDS
| Appearance | Amber, liquid |
|---|---|
| Viscosity @ 40 deg C, cSt, ASTM D445 | 103.4 |
| Viscosity @ 100 deg C, cSt, ASTM D445 | 16.3 - 21.9 |
| Viscosity index, ASTM D2270 | 140 |
| Pour point, deg C, ASTM D97 | -35 |
| Flash point, deg C, ASTM D92 | 225 |
Documented presentations
- US Gallon
- 5 Gallon Pail
Confirm current package availability and order quantity with the MAXILUB sales team.
Typical values summarize the referenced PDS and are not purchase specifications. Confirm current product requirements, approvals and package availability before ordering.
Open complete PDSMatch diesel oil to engine generation and duty cycle.
Commercial diesel selection starts with the engine maker's viscosity and API requirement, then accounts for idle time, load, emissions equipment and planned drain intervals. Provide the engine population and maintenance schedule when requesting a fleet supply recommendation.
API category and OEM requirement
This listing identifies SAE 15W-50 and API CK-4/SN; confirm each requirement against the vehicle or equipment manual.
Operating load, idle time and climate
The indexed applications include Diesel engines, Fleet maintenance, and Heavy equipment service; provide the exact asset or service use with the request.
Fleet consumption and replenishment frequency
Package sizes, order quantity and delivery timing are confirmed with the commercial quote.
Common applications
Commercial sectors
Where this product enters a South Florida supply plan.
Review the purchasing priorities for the operations that commonly evaluate this product, then include the application, quantity and delivery ZIP with your request.
Commercial Fleets
Lubrication planning for vehicles that need to stay in service.
View industry guidanceHeavy-Duty Trucking
Heavy-duty lubricant supply for maintenance shops, terminals and operators.
View industry guidanceConstruction & Heavy Equipment
Fluids for equipment maintenance, hydraulic systems and field service needs.
View industry guidanceAgriculture
Lubricants and fluids for farm equipment, service crews and seasonal operations.
View industry guidanceVerified product details
| Product SKU | UL319 |
|---|---|
| Viscosity grade | SAE 15W-50 |
| API / industry specifications | API CK-4/SN |
| Package size | Quote for available package sizes |
| Country of origin | Made in USA |
Use only where the vehicle or equipment manufacturer specifies this viscosity and performance level.






