Firestone D663

Width

195 indicates the section width of a tyre in millimetres.

Aspect Ratio

65 is a tyre’s aspect ratio which is its height from the base of the tread to the rim. This number represents a percentage of the tyre’s tread width.

Tyre Construction

R means that the tyre has radial ply construction, meaning the way in which it has been constructed.

Rim

15 indicates the diameter of the wheel rim.

Load & Speed

91 V is a reference that indicates the maximum load capacity and speed at which a tyre can be safely operated, subject to the tyre being in sound condition, correctly fitted and with the recommended inflation pressure. See load index table here.

OD

Overall Diameter of the unloaded tyre in mm.

Type Definition

RFT Run Flat Technology

RRFT Repairable Run Flat Technology

MOE Mercedes Original Equipment Extended

RBT Raised Black Letters Tubeless

OWT Outline White Letters Tubeless

RWT Raised White Letters Tubeless

TL Tubeless

TT Tube Type

XL Extra Load