The Road Vehicles (Construction and Use) Regulations 1986

Power to weight ratio

45.—(1) Save as provided in paragraph (2), every wheeled vehicle which is propelled by a compression ignition engine and which is required to be equipped with a plate by regulation 66(1) shall be so constructed that the power of its engine, calculated in accordance with paragraph I of Part III of Schedule 8, is at least 4.4 k W for every 1000 kg of the relevant weight.

(2) Paragraph (1) does not apply to—

(a) a heavy motor car or motor car first used before 1st April 1973;

(b) a vehicle manufactured before 1st April 1973 and powered by a Perkins 6.354 engine; or

(c) a bus.

(3) Every vehicle to which this regulation applies shall—

(a) if it is equipped with machinery or apparatus forming part of the vehicle or mounted on it and used for purposes not connected with the driving of the vehicle;

(b) if that machinery or apparatus is designed for use, or is likely to be used, when the vehicle is in motion on a road at a speed exceeding 5 mph; and

(c) if the power absorbed by that use is provided by the engine propelling the vehicle,

be so constructed that, when that machinery or apparatus is being used, the power of the engine remaining available to drive the vehicle is at least 4.4 kW for every 1000 kg of the relevant weight.

(4) In this regulation “relevant weight” means—

(a) if the vehicle is equipped with a plate in accordance with regulation 66(2)(a), the maximum train weight shown at item 8 on that plate or, if no such weight is shown, the maximum gross weight in Great Britain shown at item 10 on that plate; or

(b) if the vehicle is equipped with a plate in accordance with regulation 66(2)(b) and—

(i) is constructed to draw a trailer, the higher of the weights referred to in column 3 in item 2.1.5 in the Table in regulation 66; or

(ii) is not constructed to draw a trailer, the higher of the weights for motor vehicles referred to in columns 3 and 4 in item 2.1.4 in the Table in regulation 66.