Division 4.3 Alternative engine temperature measurementF1
In the case that measuring the coolant temperature is not feasible, on request of the manufacturer and with approval of the approval authority, instead of using the coolant temperature for the provision for cool down described in paragraph 3.9. of this Sub-Annex 6a, the engine oil temperature may be used. In that case, for all vehicles within the family the engine oil temperature shall be used.
The application of that procedure shall be included in all relevant test reports.