The units had a 20 m (65 ft 7 in) long carbody that rested on two bogies, and weighed 34 tonnes.

The main mechanical controls were directly connected by levers to the diesel engine, clutch and gearbox.

The units were reliable and, from the end opposite the engine compartment, offered passengers a wide-open view of the track.

The X 3800 burned 50–55 litres of diesel fuel per 100 km (5.1–5.1 mpg‑imp; 4.3–4.3 mpg‑US), giving the unit a range of about 700 kilometres (430 mi).

X 4046 preserved by l'association Autorail Lorraine Champagne-Ardenne, served as the setting for the song by Laurent Voulzy, "Paradoxal Système" in 1992.