| Product Code | Package Size | Unit of Measure |
|---|---|---|
| DTTQT-EA | Quart Bottle | Each |
| DTTQT-CA | Quart Bottle | Case of 12 |
| DTT1G-EA | Gallon Jug | Each |
| DTT1G-CA | Gallon Jug | Case of 4 |
| DTTTP-EA | 2.5 Gallon Jug | Each |
| DTTTP-CA | 2.5 Gallon Jug | Case of 2 |
| DTT55-EA | 55 Gallon Drum | Each |
AMSOIL Signature Series 10W-30 100% Synthetic Max-Duty Diesel Oil delivers top-tier wear protection, viscosity stability, and extended drain capability for turbodiesel pickups, heavy-duty on- and off-road equipment, and commercial fleets running the hardest miles.
Modern diesel engines operate under punishing conditions. High combustion pressures, extreme exhaust gas temperatures, and heavy soot loads all conspire to break down oil faster than ever. Turbocharged diesels in trucks like the Ram 2500 Cummins, Ford F-250 Power Stroke, and GM Duramax push oil to its limits during towing, hauling, and daily work duty. The wrong oil, or even an average one, loses viscosity control and anti-wear performance well before the drain interval is up.
6X MORE WEAR PROTECTION THAN THE DETROIT DIESEL STANDARD
Third-party testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 shows Signature Series Max-Duty delivers 6X more wear protection than the standard requires. That test evaluates how well an oil resists scuffing on cylinder liners under extreme pressure. In a side-by-side comparison with a leading conventional 15W-40 diesel oil using the same DD13 test, the AMSOIL-protected liners showed virtually no scuffing, while the competing brand's liners were severely damaged. Ring and liner wear is what kills compression, drives up oil consumption, and robs horsepower over time. This oil fights that at the molecular level.
UP TO 60% BETTER TURBO CLEANLINESS
Carbon deposits on turbocharger components restrict airflow and reduce boost efficiency. Signature Series 10W-30 synthetic diesel oil delivers up to 60% better turbo cleanliness based on the specification standards of CAT C13 2nd Ring Top Land Carbon testing. If you're running a tuned Cummins 6.7L or a Power Stroke pulling a fifth-wheel through mountain grades, the turbo is working overtime. This formulation resists the thermal breakdown that causes coking and deposit buildup in the turbo housing, keeping boost response sharp and consistent.
VISCOSITY CONTROL AND SOOT MANAGEMENT
Diesel combustion produces soot. That soot gets into the oil and causes it to thicken, which increases drag and reduces fuel efficiency. Built on top-tier synthetic base oils, Signature Series 10W-30 resists oxidation and controls soot-related viscosity increase through boosted detergent and dispersant additives. These additives keep soot particles suspended independently, preventing them from agglomerating into larger, wear-causing particles. The result is stable viscosity throughout the drain interval. In the ASTM D5293 cold-cranking viscosity test, the 0W-40 variant (DZF) offers 4X better cold-cranking ability than a 15W-40 oil. The 10W-30 (DTT) holds a CCS viscosity of 4858 cP at -25°C, well within spec and fluid enough for reliable cold starts in northern climates.
UP TO 76% LESS OIL CONSUMPTION
Oil consumption is more than an inconvenience. It means oil is getting past the rings and into the combustion chamber, where it contributes to deposit formation and emissions system fouling. Signature Series provides up to 76% less oil consumption than required by the API CK-4 standard in the Caterpillar-1N oil consumption test, recording just 0.12 g/kWh against the 0.5 g/kWh CK-4 limit. Low volatility (NOACK) numbers confirm this: the 10W-30 posts a 5.4% weight loss in ASTM D5800 testing, meaning less oil evaporates under heat and less vapor enters the intake tract.
2X BETTER RUST PROTECTION
Diesel equipment that sits between jobs or operates in humid, wet, or marine-adjacent environments is vulnerable to internal corrosion. Signature Series delivers up to 2X better rust protection based on industry-standard testing using the NMMA FC-W Rust Test. Corrosion on bearing surfaces and cylinder walls accelerates wear from the moment the engine fires. This level of rust protection matters for seasonal equipment, farm diesels, and trucks that spend downtime in coastal or high-humidity regions.
SPECIFICATIONS AND COMPATIBILITY
AMSOIL Signature Series 10W-30 Max-Duty Synthetic Diesel Oil meets or exceeds the following specifications:
The 10W-30 viscosity also meets MB 228.51. It is compatible with conventional and other synthetic diesel oils. Mixing with other oils will reduce the service life and performance benefits. Aftermarket oil additives are not recommended.
SERVICE LIFE
Heavy-duty on- and off-road diesel engines: 3X OEM-recommended drain interval, not to exceed 60,000 miles, 600 hours, or one year, whichever comes first.
Turbodiesel pickups: 2X OEM-recommended drain interval, not to exceed 25,000 miles or one year, whichever comes first.
Gasoline engines (where applicable): 2X OEM-recommended drain interval, not to exceed 15,000 miles or one year, whichever comes first.
Drain intervals may be extended further with oil analysis. Extended drain intervals are not recommended for performance-modified engines or when using biofuels containing more than 10% ethanol or 15% biodiesel (B15).
| Property | 10W-30 (DTT) | Test Method |
|---|---|---|
| Kinematic Viscosity @ 100°C, cSt | 12.1 | ASTM D445 |
| Kinematic Viscosity @ 40°C, cSt | 78.2 | ASTM D445 |
| Viscosity Index | 151 | ASTM D2270 |
| CCS Viscosity @ °C, cP | 4858 (-25) | ASTM D5293 |
| Pour Point, °C (°F) | -42 (-44) | ASTM D97 |
| Four-Ball Wear Test, Scar, mm | 0.46 | ASTM D4172 |
| NOACK Volatility, % weight loss (g/100g) | 5.4 | ASTM D5800 |
| Total Base Number | 10.1 | ASTM D2896 |
| High-Temperature/High-Shear Viscosity, cP | 3.5 | ASTM D5481 |
| Sulfated Ash Content, wt. % | 0.99 | — |
What vehicles and equipment use AMSOIL Signature Series 10W-30 Max-Duty Diesel Oil?
AMSOIL Signature Series 10W-30 100% Synthetic Max-Duty Diesel Oil (DTTQT-EA) is designed for a wide range of on- and off-road diesel applications, including auto/light truck, heavy-duty on-road, heavy-duty off-road, agriculture, motorcycle, ATV, UTV, snowmobile, marine outboard, and PWC equipment. Real-world users report running it in engines like the Detroit Diesel DD16 in semi trucks and the 6.7L Powerstroke in Ford pickups, where engine manufacturers recommend a quality 10W-30 diesel oil.
How does AMSOIL Signature Series 10W-30 diesel oil protect turbochargers under heavy towing loads?
AMSOIL Signature Series 10W-30 Max-Duty Diesel Oil delivers up to 60% better turbo cleanliness based on CAT C13 2nd Ring Top Land Carbon testing standards. It is specifically formulated to withstand the extra demands placed on the turbocharger when pulling heavy loads or running performance tunes for maximum horsepower. This helps keep turbo components clean and functioning efficiently over extended service.
What industry test data supports AMSOIL Signature Series 10W-30 Max-Duty diesel oil's wear protection claims?
Third-party testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 shows AMSOIL Signature Series Max-Duty Diesel Oil delivers 6X more wear protection than required by Detroit Diesel's standard. Independent testing also demonstrated that it keeps cylinder liners looking like new compared to a leading conventional 15W-40 diesel oil in the same DD13 Scuffing test. Additionally, it provides up to 2X better rust protection based on the NMMA FC-W Rust Test.
How does AMSOIL Signature Series 10W-30 diesel oil compare to conventional 15W-40 diesel oil?
In independent third-party testing using the Detroit Diesel DD13 Scuffing test, AMSOIL Signature Series Max-Duty Diesel Oil provided dramatically superior cylinder liner protection compared to a leading conventional 15W-40 diesel oil, keeping liners looking like new. It also resists thermal breakdown better than conventional and competing synthetic diesel oils, retains viscosity after high-temperature service, and provides up to 76% less oil consumption than required by the API CK-4 standard in the Caterpillar-1N oil consumption test.
Can I extend oil change intervals with AMSOIL Signature Series 10W-30 Max-Duty Diesel Oil?
Yes, AMSOIL Signature Series 10W-30 Max-Duty Diesel Oil is formulated to confidently support extended drain intervals. It resists oxidation and the thickening effects of soot contamination while retaining its viscosity after high-temperature service. Its up to 76% lower oil consumption than required by the API CK-4 standard in the Caterpillar-1N test means it maintains proper oil levels longer, supporting extended service between changes.
Is AMSOIL Signature Series 10W-30 diesel oil safe for diesel engines operating in extreme cold and hot temperatures?
Yes, AMSOIL Signature Series 10W-30 100% Synthetic Max-Duty Diesel Oil is engineered to excel in both extreme heat and sub-zero cold. It resists thermal breakdown better than conventional and competing synthetic diesel oils during high-temperature operation, while staying fluid in sub-zero temperatures for easier starting, improved oil flow, and reduced wear. This all-weather performance makes it suitable for diesel engines operating in the most demanding seasonal and geographic conditions.
Product Details PDF - AMSOIL SIGNATURE SERIES 10W-30 100% SYNTHETIC MAX-DUTY DIESEL OIL
