The Loadstar was powered by a six-cylinder petrol K-series engine from Austin, which generated an output of 125 bhp (93 kW) from a displacement of 3995 cc.

As a result, the Loadstar was replaced in 1956 by the Austin S201/401/501, which was also offered as the Morris WF by means of badge engineering.

This robust engine was known for its durability and was also utilized in other Austin commercial vehicles and passenger cars of the era, including the A125 Sheerline and A135 Princess.

The engine in the Loadstar produced 125 bhp (93 kW), providing ample power for the truck's intended payload capacity.

A military 4x4 variant known as the K9 was also produced and was used for several purposes including an ambulance, water carrier, recovery vehicle and radio truck.