 Initially the racer was called 125 GPC for Gran Premio Città or Grand Prix Compressore before the Formula One era.The 125 F1 used a supercharged 1.5-litre V12 engine and sported a steel tube-frame chassis with longitudinal and cross members.It had a double wishbone suspension with a transverse leaf spring in front and a torsion bar in the rear which was upgraded to a de Dion tube for 1950.