See other engines in this family
The same engine also has a main page: Chevrolet Duramax 15:1.
GMC 3.0L Duramax I6 Diesel specs: 182 ci (3.0L) 6-cylinder, 3.307 x 3.543 in (84 x 90 mm) bore and stroke, 15:1 compression. Rated 277-305 hp. DOHC.
The GMC 3.0L Duramax I6 Diesel is undersquare — the 3.5433" stroke exceeds the 3.3071" bore by 6.7% — a layout that trades peak RPM for leverage and torque low in the range. The 3.5433" stroke puts mean piston speed at 4,000 ft/min around 6,750 RPM, which is where a production bottom end is generally considered at its limit. Each of the 6 cylinders displaces 30.3 ci (497 cc).
At 15:1 this is a compression-ignition engine: the ratio is the heat source that lights the fuel, not a knock limit to be managed.
2 factory variants share these dimensions, rated from 277 to 305 hp. Factory fitments include the GMC Sierra 1500, Chevrolet Silverado 1500, Chevrolet Tahoe and 2 others.
| Displacement | 182 ci / 3 L |
|---|---|
| Bore | 3.3071" |
| Stroke | 3.5433" |
| Cylinders | 6 |
| Compression ratio | 15:1 |
| Bore/stroke ratio | 0.933 |
| Block material | aluminum |
|---|---|
| Head material | aluminum |
| Valvetrain | DOHC |
| Fuel type | diesel |
| Advertised HP | 277–305 hp |
| Bore/stroke character | 0.933 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 3,543 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 30.3 ci |
| Static compression | 15:1 — high enough that pump premium or better is normally required |
Each link opens the calculator with this engine's specs already filled in.
These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.
| Year | Advertised HP | Code |
|---|---|---|
| — | 277 hp | LM2 |
| — | 305 hp | LZ0 |