Vehicle categories

The letters M, N, O and T are not manufacturer designations but official EU vehicle categories from type approval. M covers vehicles for carrying passengers, N goods vehicles, O trailers, T wheeled agricultural and forestry tractors. The digit after the letter grades within the category by maximum mass: N1 up to 3.5 tonnes, N2 up to 12, N3 above; for trailers O1 up to 0.75 tonnes, O2 up to 3.5, O3 up to 10 and O4 above. This classification decides registration, technical requirements and often the licence class needed — but it says nothing about the make, year or condition of the vehicle. When judging an offer, read the category as a framework, not as a statement of quality.

Category N covers all motor vehicles built to carry goods, graded by maximum mass: N1 up to 3.5 tonnes, N2 above 3.5 up to 12 tonnes, N3 above 12 tonnes. In practice the 3.5-tonne line separates two worlds — below it sit vans that in many countries may be driven on an ordinary car licence, above it the truck begins with a licence class of its own. From 3.5 tonnes upward, commercial goods transport also brings tachographs and driving-time rules, and heavy commercial vehicles must carry a speed limiter in the EU. A common misconception when buying used: the category is set not by the load but by the registered maximum mass — an N2 driven empty is still an N2. Which licence class is actually required should always be checked against national law; the vehicle category is the same across the EU, the driving entitlement is not identical in every detail.

Category O covers trailers and semi-trailers, graded by maximum mass: O1 up to 0.75 tonnes, O2 above 0.75 up to 3.5 tonnes, O3 above 3.5 up to 10 tonnes, O4 above 10 tonnes. The most important technical step lies between O1 and O2: an O1 trailer normally needs no service brake of its own, while from O2 a braking system is required — which explains the marked price gap between two outwardly similar trailers. For the licence it is not the trailer alone that counts but the combination of towing vehicle and trailer; hitching an O2 to a car can push the outfit past the limit of an ordinary licence even though each vehicle alone would be permitted. When buying used it is therefore worth reading the papers of both vehicles, not just the trailer's. And the category says nothing about payload: two O2 trailers with the same maximum mass can differ by several hundred kilograms in what they can actually carry, depending on the weight of the body.

Three weight figures are regularly confused although they mean different things. Maximum mass is the officially registered upper limit of vehicle plus load plus occupants; it sets the vehicle category and must never be exceeded. Kerb weight is the vehicle ready to drive, usually including fluids and, depending on the definition, the driver. Payload is simply the difference between the two — and that is the number that counts day to day. It rarely appears in listings because it changes with every body: a crane, a refrigeration unit or a heavier box body comes entirely out of the payload while the maximum mass stays the same. Anyone comparing two vehicles of the same category should therefore set kerb weight against kerb weight rather than treat the category as proof of carrying capacity.