Factory build sheet
2021 Ram 1500 BIG Horn, Lonestar
Build 1C6SRFMM-M · 3L 6cyl · Four-wheel drive · Pickup
VIN positions 1 through 8 read 1C6SRFMM and position 10 reads M. Those nine characters define this build. Position 9 and positions 11 through 17 differ on every car.
Every 1500 whose VIN starts 1C6SRFMM and carries M in position 10 left the plant with the same engine, transmission, drivetrain and equipment listed below. We know of 100 of them.
- Decoded Jul 7, 2026
- 100 known VINs
- 3 listed for sale now
This configuration is identical to 2021 Ram 1500 BIG Horn, Lonestar 3L 6cyl Pickup (1,412 vehicles). That page carries the full record.
Factory specification
As filed by Ram with NHTSA for this build. Fields the filing does not record are left out entirely — a missing row means no recorded value, not a missing feature.
Engine
- Displacement
- 3 L
- Cylinders
- 6
- Configuration
- V-Shaped
- Engine model
- 30l v6 24v ddi dohc turbo diesel
- Engine manufacturer
- FCA
- Turbocharged
- Yes
- Horsepower
- 260 hp
- Fuel type
- Diesel
Drivetrain
- Drive type
- Four-wheel drive
- Brake system
- Hydraulic
Body & chassis
- Body class
- Pickup
- NHTSA body type
- TRUCK
- Cab type
- Crew/Super Crew/Crew Max
- Bed type
- Long
- Series
- DT
- Manufacturer
- FCA US LLC
Weight rating
- GVWR class
- Class 2F
- GVWR
- 7,001–8,000 lb
Gross vehicle weight rating is the loaded ceiling set by the manufacturer, not the car's own weight.
The same build, other model years
Ram used the VIN pattern 1C6SRFMM for 3 model years. Nothing but the year changes between these pages, so the price gap between them is depreciation on an identical car.
How this VIN pattern is read
A 17-character VIN carries two kinds of information: what was built, and which one it is. This page is the first kind — the nine highlighted positions.
| Positions | Characters | What they encode |
|---|---|---|
| 1–3 | 1C6 | FCA US LLC · World manufacturer identifier |
| 4–8 | SRFMM | Model, body style, engine and restraint system |
| 9 | × | Check digit — computed per vehicle, not part of the build |
| 10 | M | Model year — 2021 |
| 11 | × | Assembly plant |
| 12–17 | ×××××× | Production sequence number, unique to each vehicle |
NHTSA safety ratings
Crash-test results are published per model year and body style, so they cover the 2021 Ram 1500 as a whole rather than this build alone.
Overall
★★★★★ 5 / 5
Frontal crash
★★★★ ★ 4 / 5
Side crash
★★★★★ 5 / 5
Rollover
★★★★ ★ 4 / 5
15 recall campaigns are recorded for the 2021 1500. Recalls are issued per VIN range — check the VIN of the car you are looking at, not the model.
100 vehicles carry this build
Every VIN we have decoded to 1C6SRFMM-M shares the specification above.
- 100 Known VINs
- 3 Listed for sale now
Cars are filed by a fixed rule based on the VIN, so a car never moves between groups.
Neighboring configurations
Other factory configurations of the 1500, each with its own build sheet. The set is fixed by the VIN patterns themselves, so it does not shuffle as prices or inventory move.
Keep going
Where this data comes from
Specification fields are decoded from the manufacturer's filings in the NHTSA vPIC database, keyed on VIN positions 1–8 and 10. We publish the filed values as they stand and leave out anything the filing does not record.
Vehicle counts come from the 100 VINs of this build we have seen in dealer inventory. They are a sample of the road population, not a production figure.