Interpretation ID: nht87-2.89

TYPE: INTERPRETATION-NHTSA

DATE: 09/09/87

FROM: RE MORGAN -- MILEAGE TIRE ENGINEERING

TO: R ROGERS -- MANAGER TECHNICAL SUPPORT REGIONAL TRANSPORTATION DISTRICT

TITLE: GOODYEAR MILEAGE TIRES; BRUCE RUMAGE PHONE CALL

ATTACHMT: ATTACHED TO LETTER DATED 12/09/88 TO JACK MCCROSKEY AND GLENDA SWANSON LYLE FROM ERIKA Z ZONES REDBOOK A33, STANDARD 119; LETTER DATED 09/13/88 TO LARRY COOK FROM JACK MCCROSKEY AND GLENDA SWANSON LYLE; OCC - 2539; LETTER DATE 08/26/88 TO MARVI N ORNES FROM RE MORGAN; UNDATED REGIONAL TRANSPORTATION REPORT

TEXT: Dear Mr. Rogers;

It has been brought to our attention by our Area Field Manager, Bruce Rumage, that some of your drivers have questioned the use of Goodyear DXT Tires, which have a Max speed of 35 MPH marked on them. The drivers report that they do exceed the max speed on certain areas of their runs.

Goodyear provides two different types of transit tires for stop/start operation, DXT and XT. Both tires are basically the same, primary difference is that the DXT has seven thirty-seconds more undertread than the XT tire. The same carcass with with sam e number of plies for the load requirements. Advantage to more undertread is more miles per tire, an advantage to both RTD and Goodyear to secure a longer lasting safe tire.

City Cruiser DXT Tires are marked Max Speed of 35 MPH to indicate they are not to be used in interstate service. They can be run on a local freeway; but it is not advisable to use in strictly freeway service. RTD did specify the DXT in their specificat ion and there is no reason why they would not be suitable for the RTD operation. Todate there is no sign to indicate a problem. The tire service personnel are knowledgeable to tire related conditions and have not reported any problems with the use of D XT tires in the RTD operation. Also, an advantage to using the DXT is the curbing problems in transit operations. The extra undertread also reinforces the shoulder area. Curbed tires are safe tires; but are removed when ply fabric is exposed.

Enclosed, for your information is a brochure explaining the different Mileage Tires. Please contact me if more information is needed to help ease the drivers the concerns.