Division 1.1.5 At the request of the manufacturer and if considered appropriate by the approval authority, the height, lateral position and distance from the vehicle of the cooling fan may be modified.F1

If the specified fan configuration is impractical for special vehicle designs, such as vehicles with rear-mounted engines or side air intakes, or it does not provide adequate cooling to properly represent in-use operation, at the request of the manufacturer and if considered appropriate by the approval authority, the height, capacity, longitudinal and lateral position of the cooling fan may be modified and additional fans which may have different specifications (including constant speed fans) may be used.