Tire 101


1. Brand

2. Tire Width
3-digit number that gives the approximate tire width in mm. It measures from sidewall to sidewall. 
Typically, the higher the number the wider the tire.

3. Aspect Ratio
2-digit number that gives the approximate sidewall height. It is expressed as a % of the tire width.
The lower the ratio, the smaller the sidewall height.

4. Construction
R = Radial Ply   
Radial tires are the industry standard and refers to the internal belts being 90 degrees to the direction of travel

5. Wheel Diameter
2-digit number (in inches) that indicates the tire is designed to fit on a wheel with a 16-inch diameter.

6. Load Index
2-digit number that indicates how much weight the tire is certified to carry at maximum safe inflation.

7. Speed Rating
1 letter or 1 letter/number combo which indicates the top speed at which a tire is certified under specified conditions.

8. DOT Codes
This assures that your tire complies with all Department of Transportation (DOT) safety standards. The next two numbers or letters are the plant code where it was manufactured. The last four numbers represent the week and year the tire was built. For example, the numbers 2212 mean the 22nd week of 2012. The other numbers in the middle are used at the manufacturer's discretion as a code. This information is used to contact consumers if a tire defect requires a recall.

9. ECE Approval Number
An E with a  number in a circle assigned by the Economic Commission for Europe, that declares the tire meets the minimum safety requirements of all directives applicable in the EU.

10. E-Approval Number (Noise)
An E with a number in a frame assigned by the Economic Commission for Europe, that declares the tire meets the minimum noise requirements for the EU

11. Structure Details

12. Extra Load
XL is the marking for an extra reinforced tire in order to expand the load capacity.

13. Country of Origin

14. Pattern Name

15. 3PMSF
The three peak mountain snow flake symbol proves the minimum required performance in winter conditions, the so called snow grip index under the EU regulation 661/2009. 

16. M+S
It marks the tire with the feature of having a good traction on Mud and Snow, but it does not qualify the product as a winter tire.



Checking Tread depth

Periodically, you should check your tires for wear and damage problems. One easy way to check for wear is by using a tire pattern gauge:

  1. Use the pattern gauge as shown in the picture
  2. Read the measures on the scale
  3. Compare your pattern depth with the specifications of the national legislation. Your tires should be immediately changed, when your pattern depth is below the required measures.


Checking Tire Pressure

Be sure to check your tire pressure at least once a month and before any long road trips.  Tire pressure should be checked when they are cold – driven less than a kilometer.  Otherwise, your tires will have heated up, increasing the air pressure inside them by several pounds.  You can find the OE recommended tire pressure on the placard that is usually located in the driver’s side door jam.

Under inflation causes increased stress in the sidewalls and tread area which can result in irregular wear, aquaplaning, poor fuel economy and change in vehicle handling stability.

Over inflation causes increased stress to internal materials which can result in premature failure, poor traction and change in vehicle handling/stability.

Proper Tire Pressure: Why it Matters

Driving on underinflated or overinflated tires compromises any or all of the following.

Stopping distance: Properly inflated tires maximize tread contact with the pavement, and traction along with it. Stopping with improperly inflated tires takes more distance to stop the vehicle in an emergency situation. 

Ride and handling: When the tires have too much air, they're overly rigid, which means they don't absorb as much impact, so the car rides rougher and suspension components wear faster. An overinflated tire's tread may crown, allowing only the center portion to contact the pavement, which decreases traction. When the pressure is too low, the ride might be softer, but the tread may not meet the road uniformly.

Fuel economy: Underinflated tires greatly reduce fuel economy. 

Treadwear: Along with the traction decrease that comes with overinflation, it also causes the tread to wear more quickly in the center. Underinflation causes wear closer to the sides and allows more heat buildup, speeding wear. 

Load bearing: Each tire is rated to carry a maximum amount of weight at a prescribed tire pressure. Some cars specify a higher pressure for greater loads. At best, a tire that's underinflated for the load at hand will suffer the problems detailed above. Extra heat generated in the tire can cause it to fail even if it had held up under a lighter load. 

Tire Rotation

Regular rotation helps extend the life of your tires and improve performance because each tire carries a different amount of weight, making them wear at different rates. During rotation, each tire and wheel is removed from your vehicle and moved to a different position to ensure that all tires wear evenly and last longer. 


Balancing Your Tires

When tires are unbalanced, ride quality and tire life are significantly impacted. An unbalanced tire is usually detectable by vibrations in the steering wheel at higher speeds.  Tires should be inspected by a professional as soon as possible to avoid excessive wear and damage.


Aligning your tires ensures that all of them are adjusted to travel in the same direction.  Daily impacts such as potholes can knock your vehicle out of alignment. You should have the alignment checked if  you’ve hit something substantial, you see a wear pattern developing on the shoulders of the tires and/or you notice a difference in your vehicle’s handling.

Match Mounting

Kenda places red and yellow marks on the sidewalls of its tires to enable to best possible match-mounting of the tire/wheel assembly.  There are two methods of match-mounting using the red or yellow marks.

  1. Uniformity Method (red mark) 
    The red mark on the tire indicates the point of maximum radial force variation and should be aligned with the wheel assembly’s point of minimum run-out, which is generally indicated by a colored dot or notch on the wheel assembly. 
  2. Weight Method (yellow mark)
    The yellow mark on the tire indicates the point of lightest weight and should be aligned with the valve stem on the wheel which represents the heaviest weight point of the wheel.

After using either of the above methods, the tire/wheel should be balanced.


Any time you see any damage to your tires or wheels replace with spare at once and immediately see your tire dealer. When inspecting your tires, including the spare, check your air pressures. If your pressure check indicates that one of your tires has lost pressure, look for signs of penetrations, valve leakage, or wheel damage that may account for the air loss.  Always look for bulges, cracks, cuts, penetrations and abnormal tire wear particularly on the edges of the tire tread which may be caused by misalignment or underinfl atlon. If any such damage is found, the tire must be inspected by any tire dealer at once. Use of a damaged tire could result in sudden tire destruction.  All tires will wear out faster when subjected to high speeds as well as hard cornering, rapid starts, sudden stops, frequent driving on roads which are in poor condition, and off road use. Roads with holes and rocks or other objects can damage tires and cause misalignment of your vehicle. When you drive on such roads, drive on them carefully and slowly, and before driving at normal or highway speeds, examine your tires for any damage, such as cuts or penetrations.


The maximum load rating of your tires is marked on the tire sidewall. Do not exceed these ratings. Follow the loading instructions of the manufacturer of your vehicle and this will insure that your tires are not overloaded. Tires which are loaded beyond their maximum allowable loads for the particular application will build up excessive heat that may result in sudden tire destruction.  Do not exceed the gross axle weight ratings for any axle on your vehicle.  If you anticipate towing a trailer, you should see any tire dealer for advice concerning the correct size of tire and pressures. Tire size and pressures will depend upon the type and size of trailer and hitch utilized, but in no case must the maximum cold inf ation pressure of tire load rating be exceeded. Check the tire placard and the owner’s manual supplied by the manufacturer of your vehicle for further recommendations on trailer towing.


Tires should be stored in a cool dry place indoors so that there is no danger of water collecting inside them. Serious problems occur with tube type tires when they are mounted with water trapped between the tire and the tube. Due to pressurization, the liquid can pass through the inner liner and into the casing plies. This can result in sudden tire failure. Most of the problems of this nature, encountered with tube type tires, have been due to improper storage which permitted water to enter the casing between the tire and tube prior to mounting.  When tires are stored they should be stored in a cool place away from sources of heat and ozone such as hot pipes and electric motors. Be sure that surfaces of which tires are stored are clean and free from grease, gasoline or other substances which could deteriorate the rubber. Tires exposed to these materials and/or excessive heat for a prolonged period of time during storage or driving may be weakened and subject to sudden failure.


Tire mounting can be dangerous and should be done by trained persons using proper tools and procedures.  Your tires should be mounted on wheels which are in good, clean condition. Bent, chipped or rusted wheels may cause tire damage. Have your dealer check the size and condition of your wheels before mounting new tires. Be sure rim/Wheel manufacturer’s recommendations are followed. The inside of the tire must be free of foreign material.  Old valves may leak. When new tubeless tires are mounted, have new valves of the correct type installed.  Be sure that all of your valves have suitable valve caps.



Aquaplaning occurs when a vehicle begins to float on top of the water on a wet road. To reduce your risk of aquaplaning, slow down on wet roads.

Three main factors contribute to aquaplaning, or the loss of traction on wet roads:

  1. Vehicle speed: As speed increases, wet traction is considerably reduced.
  2. Water depth: The deeper the water, the sooner you will  lose traction, although even thin water layers can cause a loss of traction, even at low speeds.
  3. Tire tread depth: As your tires become worn, their ability to resist aquaplaning is reduced.