2011 Toyota Prius Owners Manual - Page 480

4-3. Do-it-yourself maintenance n Tire life Any tire over 6 years old must be checked by a qualified technician even if they have seldom or never been used or damage is not obvious. n If the tread wears down below 0.16 in. (4 mm) on snow tires The effectiveness of snow tires is lost. n Low profile tires (vehicles with 17-inch tires) Generally, low profile tires will wear more rapidly and tire grip performance will be reduced on snowy and/or icy roads when compared to standard tires. Be sure to use snow tires or tire chains on snowy and/or icy roads and drive carefully at a speed appropriate for road and weather conditions. n Maximum load of tire Check that the maximum load of the replacement tire is greater than 1/2 of the Gross Axle Weight Ratings (GAWR) of either the front axle or the rear axle, whichever is greater. For the GAWR, see the Certification Label. For the maximum load of the tire, see the load limit at maximum cold tire inflation pressure mentioned on the sidewall of the tire.(→P. 581) 4 Maintenance and care 457 PRIUS_U (OM47685U) DVD