Lancia was the first car manufacturer to use a monocoque chassis in a production car.
The breakthrough appeared in the Lancia Lambda, introduced in 1922 and produced from 1922 to 1931. Instead of relying on a separate conventional frame, its body structure carried major mechanical loads. This made the Lambda lighter and stiffer than many contemporary cars.
The Lambda also paired its structural innovation with independent front suspension, hydraulic shock absorbers and a narrow-angle V4 engine. Approximately 13,000 examples were built, making the design significant beyond a one-off prototype.
“Monocoque” is often used interchangeably with “unitary” or “unibody” construction, although engineering definitions can vary. The Lambda’s early body did not have a stressed roof, so some sources describe it more precisely as the first production car with a load-bearing unitary body rather than a fully modern monocoque.