AMSOIL Signature Series 5W-40 Max-Duty Diesel Oil
100% synthetic diesel oil option with strong cold-start flow. Verify the required viscosity and specification for your exact engine before ordering.
View 5W-40 at AMSOILCummins Diesel Guide
AMSOIL for 6.7L Cummins Diesel
Build a practical AMSOIL maintenance plan for a 6.7L Cummins tow vehicle, from diesel oil and filters to driveline fluids.
Hands-on experience
Watch the InstallationReal-world 6.7L Cummins tow-vehicle content
Our Cummins coverage is supported by an original bypass-filter installation video on a working RV tow vehicle. That gives you a practical look at the system beyond product descriptions and specification tables.
Featured AMSOIL products
These products are relevant to this guide. Click a product to view current specifications and availability for the selected application.
AMSOIL Signature Series 15W-40 Max-Duty Diesel Oil
100% synthetic diesel oil option for severe-duty applications. Confirm your engine's required viscosity and specifications before ordering.
View 15W-40 at AMSOIL
AMSOIL Cummins Single-Remote Bypass System (BMK34)
A vehicle-specific bypass filtration system for supported Cummins applications. Check AMSOIL's current fitment information before ordering.
View BMK34 at AMSOILProduct images courtesy of AMSOIL INC. Product availability and specifications can change; verify fitment before ordering.
AMSOIL options for the 6.7L Cummins
The 6.7L Cummins is used in Ram heavy-duty pickups that often tow, haul and idle for long periods. Start by matching the engine oil to the exact model year and required specification, then consider filtration, fuel-system maintenance, transmission fluid and differential gear oil as part of the complete tow-vehicle maintenance plan.
5W-40 and 15W-40 are common diesel choices
AMSOIL currently offers Signature Series Max-Duty synthetic diesel oil in both 5W-40 and 15W-40. The 5W-40 grade has better low-temperature flow at startup, while both grades behave as SAE 40 oils at operating temperature. Always verify the specification required for your particular truck before ordering.
Think beyond engine oil
A hard-working Cummins tow vehicle also depends on clean fuel, effective filtration and properly serviced driveline fluids. Our related pages cover bypass filtration, diesel fuel-filter maintenance, transmission fluid and differential gear oil.
6.7L Cummins AMSOIL Oil Bypass Filter Install
See a real-world bypass-filter installation on a Cummins-powered RV tow vehicle. This original video adds practical context to the filtration options discussed on this site.
Related AMSOIL guides
Frequently asked questions
What AMSOIL oil should I use in a 6.7L Cummins?
Use the viscosity and performance specification required for your model year and operating conditions. AMSOIL offers diesel oils in several viscosities; confirm the exact match with the AMSOIL vehicle lookup and your owner’s manual.
Is 5W-40 or 15W-40 better for a 6.7 Cummins?
Both are SAE 40 oils at operating temperature, but 5W-40 flows more readily at cold start. The correct choice depends on model-year requirements, climate and service conditions.
Can towing change diesel oil needs?
Towing increases heat and load, so correct oil specification, filtration and maintenance intervals become especially important. Follow the vehicle manufacturer’s service schedule and use an oil that meets the required specification.