AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil

Understand this product

AMSOIL positions this synthetic diesel-oil family for demanding on-road and off-road engine service. Its published information emphasizes wear control, resistance to soot-related thickening, turbo deposits and temperature extremes.

For this Max-Duty grade, compare the listed applications and drain-interval conditions in the bulletin. Extended service is conditional; it is not an automatic benefit for every engine, duty cycle or filter.

Engine oil for diesel service

Match the engine’s required oil specification first, then choose an allowed viscosity for your climate and workload. A shared viscosity does not make two oils interchangeable. Modern emissions equipment, manufacturer standards and the duty cycle all matter.

The listed grade is 15W-40. This identifies one selection requirement; it does not replace the performance specification or component application. Compare this exact grade, rather than another grade in the same family, with your manual.

Specifications & product documents

Product

AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil

Brand

AMSOIL

Listed grade

15W-40

Application status

Verify the exact equipment requirement

• Read / download product bulletin (PDF) g3467.pdf · 275 KB · web-optimized copy · Downloaded October 24, 2026Original manufacturer PDF ↗

The manufacturer bulletin contains the detailed applications, test methods and any service limitations. A published typical test value is not a guarantee for every operating condition. “Recommended for” language should not be read as a claim of formal manufacturer approval.

Official AMSOIL product information ↗ · Listing reviewed October 24, 2026. Local PDFs are web-optimized saved copies; consult the official source for later revisions.

Use it as part of a complete service plan

Use the current product bulletin to compare the exact grade with the engine manual. Keep oil and filter service records together. Follow the applicable manufacturer interval unless a documented AMSOIL recommendation permits otherwise; oil analysis can help monitor a managed maintenance program.

Before you order

1. Confirm the exact product, specification and application.
2. Check the package size or part number below.
3. Review the current label and bulletin for restrictions.
4. Complete your purchase on AMSOIL.com using the selected package.

Need help narrowing the choice? Contact Kyle Holdridge with the equipment model and required specification.