Interpretation ID: nht72-6.21

DATE: 07/25/72

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Sheller-Globe Corporation

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of June 23, 1972, concerning the Certification and related regulations (49 CFR Parts 567. 568). You indicate in your letter that many school bus bodies are exceeding by small amounts the weight ratings specified for the chassis by the incomplete manufacturer, and that increasing the capability of the chassis results in expenditures which you believe are not justified by the additional safety achieved. You indicate also that you believe that section 567.5 requires the final-stage manufacturer to use the incomplete vehicle ratings for his ratings, except when differing tire sizes are specified in accordance with 567.4(h).

You appear to be misinterpreting the regulations. There is no requirement that a final-stage manufacturer use the ratings provided by the incomplete vehicle manufacturer. The final-stage manufacturer is free to raise them for purposes of certification, as long as the values he chooses are consistent with the definitions of GAWR and GVWR. If he does raise them, however, he can no longer rely on the assurances of the incomplete vehicle manufacturer as to conformity with the standards, but will be responsible, subject to the Vehicle Safety Act's penalties, for (1) conformity of the vehicle with all applicable standards, and (2) ensuring that no safety problem has been created. If the final-stage manufacturer will not assume this responsibility, in our opinion he cannot reasonably maintain that the limitations imposed by the incomplete manufacturer's ratings are unjustified.

In short, you are free to choose and combine your components as you see fit, as long as you use due care to ensure that the vehicle conforms to the standards and contains no safety-related defects. Observing the component manufacturer's maximum load ratings is usually the easiest way to do this.