The engine was the 1,628 cc four-cylinder water-cooled unit which by now powered the 7C version of the manufacturer's Traction passenger car, which also provided the van's three-speed manual transmission and front torsion-bar suspension and (still innovative) front-wheel drive drive-train. The van's rear suspension came from a very simple leaf-spring arrangement. The carrying capacity was a little greater than had initially been envisaged by Boulanger, which presumably led to a firming of the rear suspension settings. The light weight of the van's body, the lack of weight balance resulting from positioning the engine and driver at the extreme front of the vehicle and the very rudimentary nature of the rear suspension meant that drivers quickly learned that without the weight of a load in the van, it was excessively prone to tail slide. The hydraulic braking system also came from the Traction, though the drum brakes were the slightly larger ones from the 1911 cc Traction 11 version.