What is the Cummins B6.7?
The B6.7 is a Cummins medium-duty diesel designation. Cummins publishes truck-specific entries as well as other applications in its product range. Do not assume that a pickup, industrial or other B-series rating describes the commercial truck you are evaluating.
What matters in a comparison
On a B6.7 truck, match the serial number to the correct vehicle application and rated output. Then assess the completed vehicle, including permanent body equipment and payload. For local work, compare engine hours and stop patterns alongside distance. A low acquisition price deserves a separate service-history check; the engine family name alone cannot establish remaining life or a future repair budget.
Fluids & filters
On-highway B6.7 CM2350 fluid guidance; do not transfer these filter examples to Ram pickup installations.
Reference checked:
Identify the unit first
Use these details to match the manufacturer's application record before choosing a fluid or ordering a filter.
- Truck VIN
- Engine model and serial number
- Engine emissions/model year
- Installed filter-housing model and original part number
- Factory coolant label and subsequent coolant-change records
Fluid specifications
Engine oil
Cummins CES 20086 or CES 20081; SAE 10W-30 or 15W-40 recommended.
B6.7 CM2350 QRG 5544259. Check the serial-specific manual for cold-weather viscosity and later generations.
Source 1 ↗Engine coolant
Fully formulated coolant meeting Cummins CES 14603; 50/50 suitable water/antifreeze or appropriate premix.
B6.7 CM2350 QRG. Preserve installed chemistry and confirm CES approval on the coolant documentation.
Source 1 ↗Filter numbers & cross-references
A catalogue cross-reference links part numbers. It does not confirm that either part fits every version of this model. Match the original part to the unit first, then check the replacement manufacturer's application and any supersession.
Engine oil filter — exact-number cross-reference
First identify this exact original part through the OEM lookup for your engine serial number and VIN. On-highway truck catalogue example; do not assume Ram B6.7 filter fitment. The catalogue cross-reference alone does not confirm fitment on every engine in this family.
Application not established by this cross-reference. Confirm this original part number in the manufacturer’s parts catalogue for the exact model and serial number before considering an alternate.
Source 1 ↗Manufacturer catalogue cross-references
- Donaldson P550428Check catalogue ↗
Fuel filter — exact-number cross-reference
First identify this exact original part through the OEM lookup for your engine serial number and VIN. On-highway truck catalogue example; not a universal B6.7 fuel-filter number. The catalogue cross-reference alone does not confirm fitment on every engine in this family.
Application not established by this cross-reference. Confirm this original part number in the manufacturer’s parts catalogue for the exact model and serial number before considering an alternate.
Source 1 ↗Manufacturer catalogue cross-references
- Donaldson P553009Check catalogue ↗
Cummins parts catalog — identify the engine serial number ↗
Cummins QuickServe — serial-specific service information ↗
What still needs unit-specific confirmation
- Confirm current part supersessions and vehicle-specific fitment through the OEM before ordering. Quantities, capacities and maintenance intervals require the serial-specific manual.
Official service and parts references
Source 1 ↗ Source 2 ↗ Source 3 ↗ Source 4 ↗Follow the current manufacturer's manual for the identified unit. This page does not set a drain interval, fill quantity or repair procedure.
Questions to take to the supplier
- Which commercial-truck rating is fitted?
- What body and auxiliary load does it support?
- Are hours, maintenance and fault-history records available?
Sources & limits
Manufacturer material supports the identification and overview above. Comparison considerations and supplier questions are Truck University’s original editorial interpretation, prepared with AI assistance. They are not an independent performance test or expert inspection.
Model-family reference only. Availability, specifications and service requirements can differ by year, market and configuration. Verify the actual vehicle or component using its identification and current manufacturer documentation. Do not use this page as a parts-fitment, modification, repair or loading instruction.
Published specifications and examples retain their labelled units; the header preferences apply to calculators.
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