Cummins VIN Decoder
Decode your VIN free to confirm a Ram Cummins diesel and its displacement. From NHTSA data, no signup.
Modern road VIN: 17 characters, no I / O / Q. Find your VIN.
Try an example:
Examples demonstrate the public data source; they are not vehicles offered for sale. Missing fields mean not reported, not “none.”
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Specifications reported by NHTSA. Empty data does not mean the feature is absent. Compare configuration labels and manufacturer records before buying parts.
About the Cummins
Built by
Cummins — in Ram 2500/3500 Heavy Duty
Fuel: Diesel
Displacements
6.7L inline-6 turbodiesel · 5.9L inline-6 (1989–2007)
Common in
Ram 2500, Ram 3500, Ram 4500 / 5500
Cummins builds the inline-six turbodiesel that powers Ram Heavy Duty trucks. The current 6.7L followed the legendary 5.9L (the 12-valve and 24-valve versions from 1989–2007). The engine is a Cummins, but the truck — and therefore the VIN — is a Ram, so the VIN decodes as a Ram and the engine shows up as the diesel.
The 8th VIN character encodes the engine, but the exact code is model- and year-specific. Decode your VIN above and read the fuel-type and engine fields to confirm the Cummins diesel, then match the model year to the 5.9L or 6.7L generation.
OPTIONAL CHECKING TOOLS
Tools for reading a hidden marking
For a VIN plate, engine stamping or equipment label you cannot see clearly, a small light or mirror may help.
Telescoping LED inspection mirror
An adjustable lighted mirror for viewing a serial plate or engine marking at an awkward angle.
Inspect only with the vehicle or machine safely parked, switched off and cool.
View on AmazonLE LED pen flashlights
Two pocket lights with clips for reading VIN plates, equipment labels and engine markings.
Each light uses two AAA batteries (not included).
View on AmazonAs an Amazon Associate I earn from qualifying purchases. Check price and fit on Amazon.
How your VIN shows the Cummins
On most vehicles the 8th character of the VIN encodes the engine — but the specific letter or number that means a given engine is make-, model- and year-specific, so there is no universal code to look up. The dependable method is to decode the whole VIN and read the engine and fuel fields, which is exactly what the free tool at the top of this page does. See how VINs encode the engine for the full explanation.
Remember the VIN reflects the factory-installed engine — a later engine swap is not recorded in the VIN.
Makes that use the Cummins
Cummins VIN — FAQ
How do I know if my Ram has a Cummins?
Decode the VIN and read the fuel type and engine fields — a Cummins Ram returns a diesel inline-6 (5.9L or 6.7L). Gas Ram HD trucks show a HEMI V8 instead.
Is my Cummins a 5.9 or a 6.7?
The decoded displacement tells you, and the model year confirms it: the 5.9L ran through 2007, and the 6.7L took over from 2007–08 onward.
Other engine families
See also the VIN year chart or decode any VIN.