Polski Fiat 621

Polski Fiat 621 was a Polish 2.5-tonne truck, the basic lorry of the Polish Army during the 1930s. A licence-built version of the Italian Fiat 621, it was heavily modified to better suit Polish needs and cope with bad roads of Poland. The undercarriage was produced in two variant: Polski Fiat 621 L was the basic variant to receive a number of superstructures while Polski Fiat 621 R was used as the basis for a line of successful buses for the civilian market and heavier, 3-tonne lorries for the army.

The modifications to the original Fiat design included:
 * strengthened undercarriage (frame, front and rear axles)
 * new leaf springs, joints and shock absorbers
 * wider wheelbase
 * redesigned mounting of cab doors
 * larger fuel tank in gasoline and diesel versions
 * cylinder block redesigned and produced of high-quality steel
 * Weber carburettor replaced with a simpler and easier to maintain construction by Solex

Serial production started in 1935 at the Państwowe Zakłady Inżynieryjne Works and lasted until 1939. In 1940 the production was to be replaced with PZInż 703 family of trucks, but the outbreak of World War II and invasion of Poland ceased all production.