A commercial vehicle including a diesel engine, a lower vehicle structure defining a vehicle floor, and, to a side, a running board providing access to a front seat of the vehicle, the lower structure supporting, under the floor, a gas oil tank including a filling pipe leading to the side of the vehicle, in a rear of the running board. The vehicle further includes a urea tank housed in immediate vicinity of the gas oil tank, and includes a filling pipe which leads into a rear front wall of the running board at a housing formed in the front wall of the running board and closable by a trap.