Tire Size For My Car - A Guide To Understanding Your Car's Tires

Understanding Tire Size For My Car

tire-size-for-my-car

Most people wonder why it is so important to get the right tire size for my car. These rubber wonders keep cars on the road and responding to drivers’ instructions. Tires are carefully selected for each make and model of vehicle and take into consideration performance capabilities and load capacities. Since tires help keep drivers and passengers safe, driving on the right sized tire improves handling which saves lives and avoids injuries to human bodies. Tires also absorb road impacts making this form of transportation more comfortable and smoother.

Understanding Tire Codes

Using P185/60 R14 82H as an example, these letters and numbers stand for:

P designates the type of vehicle, passenger
185 shows the width of the tire in millimeters
60 presents the ratio of the sidewall height to the tread width
R tells the type of tire with R for radial, D for diagonal and B for belted
14 is the rim size the tire will fit
82 correlates load capacity, this number ranges from 71 at 761 # to 110 at 1060 #
H allocates the maximum speed

Everything pertaining to tires is checked, rechecked, tested and retested. After all, lives and safety depend on correct tire size and the tire’s ability to hold the road.

The rating for speed takes into consideration two components: the tire’s ability and the vehicle. To get their ratings, each tire undergoes tests at an indoor laboratory with ideal conditions. The tire is guaranteed to perform at maximum speed under these conditions.

However, in real life, drivers may not get the same results because of improperly inflated tires, prior damage, vehicle abilities or road surfaces. In addition, load limit indexes also use ideal situations in test; the tires may not perform as well on the road under adverse circumstances. Exceeding this load limit can interfere with steering and even force blowouts.
Speed ratings also match the maximum speed the car is capable of producing to the product. This is an added safety factor. Higher tire performance protects occupants if drivers occasionally put the pedal to the metal and exceed speed limits.

Speed Symbols

Common tire symbols and maximum speed in miles per hour are:

Q 99
R 106
S 112
T 118
U 124
H 130
V 149
W 168
Y 186
Z Above 186

Of course, just because the product is rated for 118 mph does not mean it is safe or practical to drive 118 mph. This letter simply shows test performance.

Tread Wear, Traction and Temperature Information

Tire manufacturers include a tread wear, traction and temperature ratings on each unit they make. When tires are designed, they are tested against a Course Monitoring Tire which has a rating of 100. If the product is rated 200, it lasted twice as long as the Course Monitoring Tire in the test. Consumers use this information to evaluate differences in cost.

A product with a 400 rating should last twice as long as products rated at 200. Traction measured stopping distance on wet pavement using designations of AA, A, B and C with C taking the longest distance to come to a complete stop. Temperature designations are A, B and C with A rated tires performing best for long distance driving or in extremely high temperature areas.

Tread

Matching the car tire tread to the use improves performance and driver satisfaction. A tire on a high-performance vehicle has small voids between the lugs providing maximum contact with the road. Softer rubber provides more traction and better responses but wears faster. Highway patterns have long life, comfortable rides and provide the best gas mileage. However, for adverse weather conditions like wintertime driving, a mud and snow style improves traction because the special tread moves mud and rain to the tire’s edges.

Tire Inflation

Proper tire inflation is very important. Overinflated tires have narrower bands of rubber making contact with pavement; this impacts the automobile’s response to driver’s commands. Underinflated tires put stress on the sidewalls and allow sway.
It is important to match the tire to the vehicle exactly. Tires are especially designed for each car to give maximum performance and increase safety. Smart drivers do not risk their and their passengers lives and well-being to just any piece of rubber. These people insist on the right tire size for my car and know they have done everything they can to protect themselves and their loved ones.