The AS 901 SM delivers high work rates and perfect handling whether on slopes, in dense growth or high grass. A Briggs & Stratton Vanguard Series 2-cylinder engine with 480 ccm displacement, up to 16.0 hp and an oil and fuel pump performs in tough conditions without the risk of engine damage. Propulsion occurs via a 5-speed manual transmission with reverse gear (1.8 km/h) that covers a speed range from 1.2–4.0 km/h. The rear axle differential is permanently locked, resulting in excellent traction even on wet grass. Twin tyres ensure even greater traction and stability while a vertically installed engine provides a low centre of gravity and balanced distribution of weight, at a total of 215 kg.