[1] The engine initially displaced 9.4 L (574 cu in)[1][6] with bore and stroke both being 100 mm (3.9 in) and with a compression ratio of 5.0:1,[1] delivered 220 hp (160 kW) at 3000 rpm.

[6] To demonstrate the high quality engineering and reliability of the J12, one car was driven from Paris to Nice and back without needing oil or water.

When the Spanish Civil War broke out in 1936, the bodied car was still in the French Hispano-Suiza plant, and in 1938 Miguel Mateu y Pla, one of the owners of the company, decided to deliver it to the Nationalists side.

The car was then sent to the Fichet plant in Marseille to receive its armor plate and eventually delivered to the then new Spanish Government.

Mohammad Reza Shah was given a J12 by his father in 1931 at the age of 12, right before taking part in Institut Le Rosey school in Switzerland.