Interpretation ID: nht87-1.91

TYPE: INTERPRETATION-NHTSA

DATE: 06/04/87

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: Mr. Paul Utans

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Paul Utans Vice President Government Affairs Subaru of America P.O. Box 6000 Cherry Hill, NJ 08034-6000

Dear Mr. Utans:

This responds to your letter of April 21, 1987, concerning the Pact 581 Bumper Standard. You asked whether a vehicle equipped with a suspension system whose height is adjustable by the driver is tested at the manufacturer's engine-on and engine-off nominal design height.

On May 6, 1986, I responded to a similar request that you made for an interpretation. My letter (copy enclosed) stated that it is our interpretation that a vehicle must be capable of meeting the standard" damage criteria at any height position to wh ich the suspension can be adjusted.

Your current request for an interpretation does not provide new arguments which indicate that our earlier interpretation was incorrect. Therefore, I must reaffirm that earlier opinion.

As we indicated in the May 6, 1986 letter, we appreciate your concern that the very reason that thy adjustable height is provided (increased ground clearance and ramp angle for special operations) is partially negated by requiring bumpers to extend lo w enough to provide Part 581 protection at the elevated settings. The letter stated, however, that if the agency were to consider establishing special provisions in Part 581 for vehicles with adjustable suspension height control systems, it would need to be done in rulemaking. See section 102(c)(1) of the Motor Vehicle Information and Cost Savings Act.

I would also note that in a meeting in March of this year, a member of my staff advised your representatives Chat your company could submit a petition for rulemaking requesting an amendment to Pact 581. The procedures for submitting a petition for rulema king are set forth at 49 CFR Pact 552. If You should submit a petition, the agency would decide whether to grant it in accordance with statutory criteria.

Sincerely, Erika Z. Jones Chief Counsel Enclosure

April 21, 1987 Erika Z. Jones, Esquire Chief Counsel National Highway Traffic Safety Administration 400 7th Street, S.W. Washington, D.C. 20590

Re: Interpretation of 49 CFR Part 581, Bumper Standard

Dear Ms. Jones:

Subaru of America, Inc. (SOA) requests an interpretation of 49 CFR Part 581, Bumper Standard, with respect to the test conditions applicable to passenger motor vehicles other than multipurpose passenger vehicles that have a suspension system whose height is driver-controllable under certain limited operating conditions.

SOA would like confirmation of its interpretation that, because height of an adjustable suspension system is not specified as one of the conditions in S581.6, compliance with the Bumper Standard is demonstrated at the manufacturer'; engine-on and engine- off nominal design height.

The Subaru air suspension system (fitted only to top-of-the-line, four-wheel-drive vehicles) maintains constant ground clearance regardless of vehicle load by adjusting the volume in each of four air springs in accordance with a signal from a vehicle hei ght sensor installed in each air spring. For driving on poor or snow-covered roads, with four wheel drive engaged, the driver may activate a switch to select a "High" suspension position offering increased ground clearance. This "High" setting is intende d for use only in special circumstances where-extra ground clearance is desirable. Having to meet the Part 581 pendulum requirements at such setting would partially negate the increased clearance intended to be provided, particularly ramp angle. When the ignition is switched to the "off" position, the suspension returns to "normal" for parking to ensure that the bumpers provide proper protection. When the ignition is switched to the "on" position, "High" ground clearance must be reselected, if desired.

SOA has no indications that its present air suspension system vehicles are being operated in the "High" position under conditions other than those intended and recommended by Subaru. (Demographics of the owners of these vehicles show more of them to be m arried, older, better educated and affluent than those of competing vehicles.)

Although the standard does not take into account load variances that can result in changes in bumper height (and therefore the level of protection provided) the Subaru system is load-compensating and therefore offers the same protection at various condit ions of vehicle loading, as well as preserves headlamp aim.

Subaru is currently studying the feasibility of certifying its MPV's as passenger cars. However, testing at the "High" ground clearance position would make it literally impossible for four wheel drive MPV's with variable height air suspension systems to meet passenger car bumper standards, in spite of the 5 mph systems new for the 1987 model year.

Should you need further information about this request, please contact Mr. Alfred Gloddeck in SOA's Washington office, telephone (202) 295-4994.

Sincerely, SUBARU OF AMERICA INC. Paul Utans Vice President Government Affairs