AMSOIL Signature Series Max-Duty 15W-40 Synthetic Diesel Oil
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3 units available for local pickup
at National Synthetics — arrange pickup
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The Classic Diesel Workhorse Viscosity
AMSOIL Signature Series Max-Duty 15W-40 is the traditional heavy-duty diesel viscosity, now with 6X more wear protection. With the lowest NOACK volatility in the Max-Duty lineup at just 5.1%, it delivers minimal oil consumption for long-haul and heavy-duty applications.
Key Benefits
- 6X more wear protection than required by DD13 Scuffing Test
- Lowest NOACK volatility (5.1%) in the Max-Duty lineup
- 76% less oil consumption than API CK-4 standard
- Thickest protective film (HTHS 4.5 cP)
- Extended drain intervals up to 3X OEM recommendation
- 2X better rust protection
Technical Specifications
| Property | Value |
|---|---|
| Kinematic Viscosity @ 100°C, cSt | 15.6 |
| Kinematic Viscosity @ 40°C, cSt | 116.4 |
| Viscosity Index | 142 |
| HTHS Viscosity, cP | 4.5 |
| Pour Point | -40°C (-40°F) |
| NOACK Volatility, % weight loss | 5.1% |
| Total Base Number (TBN) | 10.1 |
| Sulfated Ash Content | 1.0% |
Industry Certifications & OEM Approvals
API
- CK-4/SN
Cummins
- CES 20086, CES 20081
Detroit Diesel
- DFS 93K222, 93K218
Volvo
- VDS-4.5
Mack
- EOS-4.5
Chrysler
- MS-10902
Pros and Cons
Pros
- 6X more wear protection than required by DD13 Scuffing Test
- Lowest NOACK volatility (5.1%) in the Max-Duty lineup
- 76% less oil consumption than API CK-4 standard
- Thickest protective film (HTHS 4.5 cP)
- Extended drain intervals up to 3X OEM recommendation
- 2X better rust protection
Cons
- Premium Investment: Higher initial cost compared to conventional or "shelf-brand" synthetic oils.
- Limited Local Retail: Primarily available through authorized dealers and specialized synthetic outlets. National Synthetics is a local stocking dealer. Call 1-678-944-8816 to confirm in-stock items for same-day local pickup.
Get AMSOIL Signature Series Max-Duty 15W-40 Synthetic Diesel Oil Today
Order directly through National Synthetics for Preferred Customer pricing and fast shipping.
SHOW MY PRICEIndependent AMSOIL Dealer #1858536
Shipping & Returns
Fast, Reliable Shipping
- Free standard ground shipping on orders of $100 ($130 in Canada) or more.
- Orders under the threshold ship for a flat $9.99 ($12.99 in Canada) freight charge.
- In-stock items typically delivered in two to three business days.
- U.S. and Canada only — no shipments to PO Boxes.
30-Day Return Policy
- Return unopened, currently marketed products within 30 days for a full refund (minus freight).
- Exchange unopened products within 90 days with no restocking fee.
- Special-order items are non-returnable.
- Returns are handled directly by AMSOIL.
Frequently Asked Questions
15W-40 provides a thicker film at operating temperature (HTHS 4.5 vs 4.3 cP) and the lowest NOACK volatility for minimal oil consumption. However, 5W-40 offers better cold-weather performance. Use whichever viscosity your engine manufacturer recommends.
Independent AMSOIL Dealer #1858536. Product information sourced from AMSOIL. Visit AMSOIL.com for the most current product details and availability.