Division 2.8 F1
In the case of multi stage type approvals or individual vehicle approval where the base vehicle is a complete vehicle with a valid certificate of conformity, the final stage manufacturer shall consult the base vehicle manufacturer to set the new CO 2 value in accordance with the CO 2 interpolation using the appropriate data from the completed vehicle or calculate the new CO 2 value on the basis of the parameters of the completed vehicle as specified in paragraph 3.2.4. of Sub-Annex 7 of Annex XXI and using the tool supplied by the manufacturer of the base vehicle as mentioned in paragraph 2.3. above. If the tool is not available or the CO 2 interpolation is not possible, the CO 2 value of Vehicle High from the base vehicle shall be used with the agreement of the approval authority.