Interpretation ID: nht81-3.36

DATE: 11/12/81

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: General Motors Corporation

TITLE: FMVSR INTERPRETATION

TEXT: This responds to your letter of September 17, 1981, requesting NHTSA's confirmation that certain small, utility-type vehicles to be produced by General Motors would be classified as "light trucks" for fuel economy standards compliance purposes. In your letter you point out that these future vehicles, at least in base form excluding optional rear seats, would have greater cargo-carrying volume than passenger-carrying volume, a criterion for classifying vehicles as light trucks under our regulations.

As you correctly note, SAE Recommended Practice J1100a specifies that cargo and passenger volumes are to be determined on the basis of a "base" vehicle, i.e., one without optional equipment. Further, EPA regulations set forth in 40 CFR 600.315-79(c) provide that all dimensions and volumes are to be determined from base vehicles without options, for purposes of grouping vehicles in classes of comparable vehicles. Strictly speaking, however, neither the SAE Practice nor the EPA provision explicitly apply to the determination of cargo-carrying volume for utility vehicles under our vehicle classification regulations in 49 CFR Part 523. Those regulations are silent on the issue of the inclusion of options for determining interior volume.

Nevertheless, to achieve uniform treatment for passenger automobiles and light trucks and to reduce the complexity of accounting for different variations of vehicles sold based on optional equipment, we interpret Part 523 to require that vehicle classification be determined on the basis of the vehicle without optional equipment installed. Therefore, we agree that two-wheel drive utility vehicles which are truck derivatives and which, in base form, have greater cargo-carrying volume than passenger-carrying volume should be classified as light trucks for fuel economy purposes.

Environmental Activities Staff

General Motors Corporation

September 17, 1981

Michael M. Finkelstein Associate Administrator for Rulemaking National Highway Traffic Safety Administration

Dear Mr. Finkelstein:

In response to General Motors' March 31, 1980 question on vehicle classification for fuel economy purposes, your August 12, 1981 letter stated the Energy Policy and Conservation Act would not permit NHTSA to classify two wheel drive utility vehicles, i.e., Blazer and Suburban, as light trucks for off-highway use if they were under 6000 lbs. Vehicles designed to perform "truck-like" functions on-highway can also be classified as light trucks. We realize your agency must work within the requirements of the statute and the 6000 lb. GVWR limit cannot be changed by regulation. However, your letter did not consider the alternative on-highway classification route for utility vehicles to be classified as light trucks.

49 CFR Part 523.4(a)(4) of the fuel economy regulations allows a two wheel drive vehicle under 6000 lbs. GVWR to be classified as light truck if the cargo-carrying volume is greater than the passenger-carrying volume. The cargo and passenger volumes are determined in accordance with the procedures outlined in the Society of Automotive Engineers Recommended Practice J1100a, Motor Vehicle Dimensions (Report of Human Factors Engineering Committee, SAE, approved September 1973 and last revised September 1975). All dimensions are measured to the base vehicle and do not include Regular Production Options (RPO). Both our current Blazer and Suburban offer a folding second seat as an option. The cargo volume easily exceeds the passenger volume on the base models without the optional second seat. These models are designed for commercial use and their cargo carrying capability is significant without the second seat. Therefore, these vehicles qualify as light trucks independent of the 6000 lb. GVWR requirement. When we produce future downsized utility models, less than 6000 lb. GVWR, these vehicles will also qualify as light trucks if their cargo volume exceeds the passenger volume on the base vehicle.

More important, the critical issue in utility or multipurpose vehicle classification is their cargo carrying capability which is inherently derived from the base pickup truck. NHTSA agreed with this truck derivative implication in their Vehicle Classification Final Rule 42 F.R. 38366(1977). Since the same truck chassis is used for both the pickup and the utility models (Blazer or Suburban) they both are light trucks.

Our future product programs are proceeding according to the above interpretation of the vehicle classification regulation. Your confirmation of this interpretation would be appreciated as soon as possible.

T. M. Fisher, Director Automotive Emission Control