Interpretation ID: nht88-3.26

TYPE: INTERPRETATION-NHTSA

DATE: 08/26/88

FROM: RE MORGAN -- MILEAGE TIRE ENGINEERING GOODYEAR TECHNICAL CENTER

TO: MARVIN ORNES -- MANAGER, TECHNICAL SUPPORT REGIONAL TRANSPORTATION DISTRICT

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 12/09/88 FROM ERIKA Z. JONES -- NHTSA TO JACK MCCROSKEY AND GLENDA SWANSON LYLE, REDBOOK A33, STANDARD 119; LETTER DATED 09/13/88 FROM JACK MCCROSKEY AND GLENDA SWANSON LYLE TO LARRY COOK -- NHTSA, OCC 2539; LETTER DATE D 09/09/87 FROM R. E. MORGAN TO R. ROGERS RE GOODYEAR MILEAGE TIRES; REF BRUCE RUMAGE PHONE CALL; BOOKLET FROM REGIONAL TRANSPORTATION DISTRICT DATED 12/01/87 EST

TEXT: Dear Mr. Ornes:

Goodyear supplies basically two type of tires for Intra City Service. City Cruiser DXT and the City Cruiser XT tire. Both are produced in the same mold and have the same number of plies.

They both are designed for identical service; but the difference comes in the amount of "Tread Rubber." DXT tires have a total of 1.40 inches of tread rubber and the XT tire has 1.18 inches. Marked on the sidewall of the DXT tire is the Max speed of 35 MPH, and on the XT is 55 MPH. The DXT may be used at higher speeds; but not for sustained operation.

Once the tread rubber is worn down for either regrooving or recapping they both become the same tire carcass and may be used for 55 MPH service. Recapping process does not add the extra undertread on the carcass but the regular amount, so the tires will run safely at the 55 MPH speed.

Please contact us if more explanation is needed.

Sincerely,