Tire designation - GF40.10-P-1020-01A
For the designation of tires as per ECE directive, with the exception of ZR tires (see example 2), the speed symbol for the permissible maximum speed is specified after the tire size.
Other important identifications
The three digit code or manufacturing code after the DOT letters and number sequence indicates the manufacture date, e.g. 452 = 45 week in 1992 (number 1 and 2 = production week, number 3 = last digit of manufacturing year).
M + S = slush and snow tires (winter tires)
All other designations are USA identification specifications.
The speed symbol "W" has been added to the usual speed symbols "Q/R/S/T/H/V/VR/ZR". This symbol identifies tires that have been approved for speeds up to a maximum speed of 270 km/h.
When installing new tires, these tires can be used as a replacement for "VR" and "ZR" tires. An entry in the registration papers is not necessary.
The speed symbol "Y" has also been added. This symbol identifies tires that have been approved for speeds up to a maximum speed of over 270 km/h.