This tank would be 12 centimetres longer than the original M14/41, and would mount a new gun originally meant for the M16/43, a new gasoline engine (the 12 litre 190 hp SPA 15TB M42, chosen due to a shortage of diesel fuel in Italy at the time) and a new drive. The vehicle, officially known as the Carro Armato M15/42 ("M" for medium tank, the weight in tonnes (15), and the year of adoption (1942)), incorporated improvements learned from the battles in North Africa; but development of the tank's main gun and ammunition meant that it could not enter production until 1 January 1943, when it was already obsolete.