Interpretation ID: nht72-4.15
DATE: 07/05/72
FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA
TO: Nissan Motor Co. Ltd.
TITLE: FMVSS INTERPRETATION
TEXT: This is in reply to your letter of June 20, 1972, on the subject of the options which may be included in the unloaded vehicle weight of a passenger car under S8.1.1 of Standard 208.
The definition of "unloaded vehicle weight" is intended to include a vehicle equipped with any combination of optional items that are installed by the factory or by the dealer with the factory's authorization. The weight of equipment installed by the dealer without authorization by the manufacturer would not be includable.
To answer your question by use of your example, you must concern yourself with both factory optional air conditioning and with dealer optional air conditioning that is authorized by the factory.