Subject:
Tyre Education (Part 1)
Message:
How to read a tyre sidewall
Tyre code, commonly molded onto the sidewall of the tyre, is described by an alphanumerical value. This code specifies the dimensions of the tyre, and some of its key limitations, such as load bearing ability, and maximum speed.
Speed Capability
The speed capability of the replacement tyres must always equal or exceed the original equipment tyres. When replacing tyres, refer to the vehicle owner’s manual for correct size.
When the tyre size contains a speed symbol, for example P205/60HR15 or P205/60R15 90H, the replacement tyre must have the same or higher speed rating symbol if the speed capability of the vehicle is to be maintained. If the replacement tyre is not speed rated, the speed capability of the vehicle is limited by the speed capability of the replacement tyre.
Speed Category
S 180 km/h (112 mph)
T 190 km/h (118 mph)
U 200 km/h (124 mph)
H 210 km/h (130 mph)
V 240 km/h (149 mph)
*W 270 km/h (168 mph)
*Y 300 km/h (186 mph)
* For tyres having a maximum speed capability above 240 km/h (149 mph), a "ZR: may appear in the size designation.
LOAD INDEX - The load index on a passenger Car tyre is a numerical code stipulating the maximum load (mass, or weight) each tire can carry.
CODE KILOGRAMS CODE KILOGRAMS CODE KILOGRAMS CODE KILOGRAMS
60 250 80 450 100 800 120 1400
61 257 81 462 101 825 121 1450
62 265 82 475 102 850 122 1500
63 272 83 487 103 875 123 1550
64 280 84 500 104 900 124 1600
65 290 85 515 105 925 125 1650
66 300 86 530 106 950
67 307 87 545 107 975
68 315 88 560 108 1000
69 325 89 580 109 1030
70 335 90 600 110 1060
71 345 91 615 111 1090
72 355 92 630 112 1120
73 365 93 650 113 1150
74 375 94 670 114 1180
75 387 95 690 115 1215
76 400 96 710 116 1250
77 412 97 730 117 1285
78 425 98 750 118 1320
79 437 99 775 119 1360
Example Tyre Designation Maximum Speed
P275/40R17 93W 270 km/h (168 mph)
P275/40R17 93Y 300 km/h (186 mph)
How to take care of your tyres
Consumers have the primary responsibility for the regular care and maintenance of their tyres. Tyres should be inspected at least once per month. The regular inspection should focus on proper inflation pressure; tread wear and tyre/wheel damage as detailed below. Having tread depth above the legal limit does not determine the service life of a tyre. Tyres must be properly maintained and routinely inspected for continued safe and proper use — even when tread depth remains. Tyres may need to be taken out of service even when tread depth above the legal limit remains. Regular inspection becomes particularly important the longer a tyre remains in use.
This monthly inspection should be supplemented by periodic rotation, balancing and alignment services. Inspection should occur whether or not the vehicle is equipped with a tyre pressure monitoring system.
Tyre rotation
It is important to check your tyres and wheels for signs of possible damage, and check your vehicle for any mechanical problems and correct if necessary. If you notice irregular or uneven tread wear, the tyres should be rotated to alleviate the problem.
You should follow the rotation pattern or procedure indicated in your limited warranty and the vehicle owner’s manual. We recommend you rotate tyres on front wheel drive vehicles and/or all season tyres on any vehicle every 12,000 km to equalize the rate of wear; however, rotate your tyres earlier if signs of irregular or uneven tyre wear arise, and have the vehicle checked by a qualified technician to determine the cause of the wear condition. The first rotation is the most important.
Besides monthly inspection of their tyres’ visual condition, consumers must also be aware of any change in dynamic performance such as increased air loss, noise or vibration. These conditions could be caused by internal damage to the tyre and may require that the tyre be removed from service immediately to prevent a tyre disablement. Consumers are recommended to consult a tyre service professional if any dynamic performance issues are noted.
Driving habits
You may not realize it, but the way you drive can have a lot to do with how long your tyres will last and how well they perform. As you head down the road, there are a number of things to keep in mind.
Avoid hard cornering, rapid accelerations and abrupt braking as they put a lot of stress on your tyres. Smooth, safe driving is not only better for your tyres, but more importantly for you as a driver too.
Watch out for overloading. Driving on an overloaded tyre is hazardous. When your car is carrying too much weight, it can create excessive heat inside your tyres—and that can cause sudden tyre failure.
Never exceed the maximum load rating of your tyres, which you can find on the sidewall of the tyre, or in the owner’s vehicle manual. When you replace a tyre, make sure the new one has a load-carrying capacity equal to or greater than the tyres that originally came with your vehicle.
Source:
www.tyrepac.com 