Know Your Tyer

Read our answers to these frequently asked questions about tyres. In addition to providing information that you may be looking for, they will guarantee that you get the best possible deal when you buy tyres for your vehicle.

1. Do JK Steel Belted Radials help in fuel saving? 2. Why should you use JK Radial tubes with them? 3. Do retreaded radials give better mileage than retreaded ordinary bias tyres? 4. Do radials enhance the comfort level while driving? 5. Just how vital inflation cause?

is

correct

inflation pressure?

What

damage

does

under-

6. What are the common reasons for tyre damage? 7. Many people fit their cars with wider tyres for aesthetic reasons, are there any technical advantages / disadvantages of doing so? 8. Is there a chance of tyre burst while running at high speeds? 9. Two of the tyres on my car are worn and need replacement, where should I fit new tyres ? 10. What inflation pressure should I have for my tyre? 11. A few parts on tyres on my car are wearing faster than other parts, what can be the reason? 12. How tubeless tyres are different from conventional with tube tyres? Which is more safe?

Do JK Steel Belted Radials help in fuel saving? JK Steel Belted radials give more than 5% fuel saving. This is made possible by the structure of radial tyres. Ordinary tyres have a crisscross ply construction. The cords in successive layers tend to move against each other in a scissor-like motion causing extra internal stress. This is absent in radial construction. Cords in radial tyres are laid radially. They flex easily - without internal stress. This means less energy is required to move the vehicle. You save precious fuel. An ideal tyre fitment arrangement would be to have all four tyres as radials. If you use only two, fit them only in the rear.

Why should you use JK Radial tubes with them? JK Radial tubes have several features which make them ideal for radial tyres. •

Made of Butyl rubber for better air retention

•

30% higher joint strength Ability to withstand higher rate of deflections

•

Higher gauges

•

Shaped to fit snugly into JK Radials. No excess stretch to cause loss of air

Do retreaded radials give better mileage than retreaded ordinary bias tyres? There are thousands of retreaded JK Steel Belted radial tyres in operation. Retreaded, they still give much more mileage than retreaded ordinary bias tyres. It is necessary to remove them for retreading while there is still 2mm of tread pattern life, when tread wear indicators appear, as shown in the picture. These TWIs show it is time to retread the tyre. It is recommended to retread radials by the latest procured process.

Do radials enhance the comfort level while driving? Yes, JK Tyre radials provide a bonus to motorists in the form of greater comfort. The supple sidewalls of the tyres act as mini shock absorbers. They ensure that less shocks pass on to the suspension. This means that your ride is more comfortable, even at high speeds. Greater Comfort With Radials

Just how vital is correct inflation pressure? What damage does under-inflation cause? It is very important to correctly inflate tyres. Do not estimate tyre pressure by appearance. Under-inflation causes fast tyre wear, steering drag, excessive fuel consumption and tyre failure. Over-inflation causes hard riding, damage to suspension and steering and uneven tyre wear. Check pressure with an accurate gauge when tyres are cool. Regularly check your pressure gauge with a standard gauge for accuracy.

What are the common reasons for tyre damage? A flat spot can be caused by heavy braking which makes the wheels lock and scrub the tyre along the road surface. Feathering is caused by bad wheel alignment, excessive toe-in or toe-out of the wheels. Uneven wear of the tread is due to bad wheel balance, or a fault in the suspension, steering gear or bearings.

Many people fit their cars with wider tyres for aesthetic reasons, are there any technical advantages / disadvantages of doing so? Although correct tyre size for normal running is the one recommended by vehicle manufacturer, For special purposes vehicle performance can be improved by selecting wider tyre with lower profile, which means maintaining same overall diameter of the tyre, lowering aspect ratio, thus increasing the tyre width. This is called up-sizing or up-stepping. There are some safety guidelines, which must be followed while upsizing, i.e., overall dimensions of the tyre must fall within certain limits. While selecting a high performance tyre following must be observed:

1. Clearance Ensure that any of the tyres does not foul with the vehicle body under any conditions. On vehicles with McPherson strut suspension, there is very much a chance that super fat tyre fouls with steering linkage. Also the tyre should not project out of the vehicle body, thereby increasing overall width of the vehicle, increasing chances of an accident.

2. Speedometer and odometer error Speedometer / odometer are connected through propeller shaft of your vehicle and are calibrated for a particular wheel overall diameter. Changing overall diameter of tyre much, may lead to erroneous readings by speedometer and odometer. In case you observe that tyre overall diameter is decreasing much, you can increase your rim size. Use following calculation to select correct tyre size for larger rim. For every 1-inch increase in rim diameter, add 20mm to tyre width and subtract 10% from aspect ratio. But be sure to check PCD of rim and fouling of new tyre/ rim assembly with other parts

Is there a chance of tyre burst while running at high speeds? Every tyre has a speed rating, which indicates the max. speed to which you can run the tyre. See " tyre terminology " section on this website for details on speed rating.

Two of the tyres on my car are worn and need replacement, where should I fit new tyres ? Many dealers and customers alike are of the view that when two tyres on a car are to be replaced , they should be fitted in front. This was the case few years ago, when it was felt that conrtrol of the vehicle was more critical to front deflations and therefore new and less vulnerable tyres should be fitted in front. But the modern recommendation by tyre industry is "New tyres to rear". This applies to both front and rear driven vehicles. Primarily its justification is increased safety particularly in wet conditions. Partly worn tyres have poor water drainage, leading to aquaplaning and thus tendency to oversteer and loss of control. Similarly straight line braking in wet can be adversely affected. "New tyres to rear " Principle may not apply to following cases:

1. Where front and rear tyres have different sizes. 2. Where two new tyres are of lower speed rating. 3. On certain 4x4 vehicles, where it would result in significant difference

in tread depths.

What inflation pressure should I have for my tyre? Correct inflation pressure is indicated on vehicle placard/ owner's manual of the vehicle. However for extreme low traction situations you may have to decrease inflation pressures. This increases foot print size of the tyre and floatation ability and aids traction. But NEVER DEFLATE YOUR TYRES UNDER 16 PSI and inflate to original pressure as soon as you return to tarmac. Also you should keep in mind that load carrying capacity of tyre is proportional to its inflation. Which implies that Inflation pressure on your tyre should be proportional to the load. Excessive inflation leads to low shock absorbing ability of tyre, impact failures or other casing failures, this also leads to excessive wear in centre. Under inflation will cause excessive wear in shoulder, heavy steering and poor handling.

A few parts on tyres on my car are wearing faster than other parts, what can be the reason? This situation is called spot wear and can be attributed to following:

1. Dynamic imbalance of tyre/ rim assembly. 2. Sudden braking and rapid starting.

3. High run out in tyre/ rim assembly. In case tyre is wearing diagonally, i.e., wear is starting from one side and progresses to other side as you move along the circumference, following may be the reasons: 1. Faulty suspension. 2. Improper wheel alignment. 3. Faulty rotating parts like brakes, etc. 4. Bent beam axle.

How tubeless tyres are different from conventional with tube tyres? Which is more safe? Tubeless tyres have a liner of specially made rubber over innermost layer of the tyre. This liner gives the tyre air tightness and sealing properties as good as a tube, not only that if a nail pierces into the tyre, liner engulfs it and prevents air from leaking out, air leaks only very slowly when the nail is taken out. Thus, come what may, a tubeless tyre never goes flat all of a sudden and hence is more safe.

Following these tips will guarantee that your JK Tyres keep running in perfect shape for mile after mile. Adopt the JK way to take care of your tyres.

Tips Tread Depth Correct Air Pressures Recommended Inflation Pressure Tyre Rotation

Tips

1. Do not use tyres with a tread depth of less

than 1.6mm. Apart from being illegal, tyres with low levels of tread will slide easily, suffer from extended braking distances and will be more susceptible to rupturing. In wet conditions the vehicle will aquaplane making braking and handling almost impossible.

2. Make sure air pressures are correct. Low air

pressure generates heat which can result in the rubber and cord separating, which in turn leads to the cord becoming cut and puncturing the tyre. Low pressure also results in excessive wear on the edge of the tyre, shortening the tyre's life. Excessive pressure, meanwhile, results in unpredictable handling in addition to which, if the tyre suffers an impact, it's easily ruptured and cut. If you brake hard, the tyre may skid, which reduces tyre life as the centre of the tread becomes worn. Check tyre inflation pressures at least twice a month. Always check pressures when tyres are cool and maintain the pressure recommended by the vehicle manufacturer.

3. Remove objects from damaged tyres. Driving with objects such as stone in the

tread groove, or with a nail stuck in the tread can puncture or rupture the tyre. You should change or repair the tyre immediately on discovering any damage to avoid any further damage to the carcass.

4. Treat abnormal tyre wear immediately. To assure normal wear you should check air pressures and alignment and rotate the tyres regularly. Advise customers to avoid bad driving habits such as sudden acceleration, braking and cornering.

5. Check the spare tyre. Check the spare tyre's air pressure, existence/non existence of damage and the depth of remaining tread.

6. Never mount radial tyres on the same axle as non-radial tyres or radial tyres on the front axle when non-radial tyres are mounted on the rear axle. These

conditions are likely to cause vehicle instability resulting in a sudden loss of control and serious injury (see Mixing Tyres). 7. Ensure wheel nuts are securely tightened.

8. Never overload tyres. The maximum load and inflation pressure of the tyres are

moulded into the sidewall. Also, remember; the tyre is capable of carrying the maximum load only if it is inflated to its maximum air pressure.

9. Do not use detergents or chemicals containing petroleum products for cleaning or polishing tyres.

10. Never fit used tyres unless their past history is known. Tyres age even if they have not been used or have only been used occasionally. Cracks in the tread or in the sidewall rubber, sometimes accompanied by deformation of the carcass, are a sure sign of aging.

11. Punctured tyres must always be removed from the wheel to check for secondary damage.

12. If it is necessary and feasible to repair a tyre, it must be carried out by a tyre specialist as soon as possible to avoid any structural deterioration. All tyre repairs must be entrusted to a tyre repair specialist.

Tread Depth

1. As per central Motor vehicle regulations (CMVR) car tyres must have a minimum of 1.6mm of tread in a continuous band throughout the centre of the tread width and over the whole circumference of the tyre.

2. To help recognise when tyres are nearing the legal limit, tyres are manufactured with tread wear indicators in the grooves.

3. However, despite the law, it is universally recognised in the tyre industry that the legal limit is wholly insufficient to protect drivers in adverse driving conditions.

4. Drivers are therefore recommended to consider replacing their tyres when the tread depth reaches 3mm.

Correct Air Pressures Setting and maintaining the correct air pressures is the first step to obtain optimum performance and life from tyres. Incorrect Inflation

1. Over inflation reduces the ability of the tyre to absorb road shocks resulting in a

much harsher ride. Excessive over inflation may lead to impact fracture or other casing failures. Over inflation will also cause excessive wear of the centre of the tyre.

2. Under inflation allows excessive flexing of the tyre, causing excessive internal heat to build up, eventually weakening the casing and causing damage. Under inflation will also cause excessive wear on the shoulder of the tyre resulting in heavy steering and poor handling. 3. Excessive pressure on the shoulder area will increase wear and reduce stopping distance.

Tyre Rotation

Front Wheel Drive

Rear Wheel Drive

Rotate your tyres every 5000km to achieve equal rate of wear.

Provided here, for your benefit, are simple definitions of technical tyre terms that will enable you to understand the technology that goes into a tyre. Learn what each part of a tyre does, and get tyre-savvy!

Tyre Placard Decoding all that information on the sidewall Tyre Sizing Systems

Other Markings Aspect Ratio (or sidewall height) Speed Ratings Load Indices

Tyre Placard

1. A vehicle's original tyre and wheel specifications are detailed on a placard affixed to all vehicles manufactured on or after the 1st of January 1973.

2. The tyres conform to specific load carrying specifications as recommended on the vehicle manufacturer's tyre placard, as required by Australian Design Rule 23 (ADR23).

3. Tyres should be appropriate to the type and size of rim fitted to the vehicle.

Decoding all that information on the sidewall All numbers, letters, symbols, mysterious codes. Here's the important stuff: A : Manufacturer or brand name, and commercial name or identity. B & J : Tyre size, construction and speed rating designations. See tyre sizes and speed ratings below. C : Denotes type of tyre construction. D : M&S denotes a tyre designed for mud and snow. Reinforced marking only where applicable. E : Load and pressure marking requirement.

Tyre Sizing Systems Over the years there has been many different methods used to size tyres. Many of these are still in use today, with the ISO Metric Sizing System the most widely used.

1. Numeric Sizing System This first system developed for tyre sizing was used until the late 1960s, but provided only the cross section width of the tyre and the rim diameter in inches. If the section width ended in zero (e.g., 7.00-14 or 7.50-14), the tyre had a common aspect ratio of about 92. For section widths not ending in zero (e.g., 8.25-15), the tyre was considered "low profile" with an aspect ratio of about 82.

2. Alphanumeric Sizing System

In 1968, a new concept was introduced worldwide. The Alphanumeric sizing system is a load-based system where tyres are designated by their load-carrying capacity and aspect ratio. The first letter is the load and size relationship, with letters ranging from A to N. The lower the letter, the smaller the size and, of course, the lower the load-carrying capacity of the tyre.

3. P-Metric Sizing System To accommodate the smaller tyres used on compact cars, the P-Metric (Passenger Metric) system was created in 1976. The maximum inflation pressures of P-Metric tyres were raised for lower rolling resistance.

4. Metric Sizing System

Because Europe primarily uses the metric system of measurement; the Metric sizing system was developed. It is essentially a conversion of the Numeric system. Section widths are notated in millimetres instead of inches. Originally, tyres not identified with an aspect ratio were assumed to be 82-series. When 60- and 70 series tyres appeared, the aspect ratio was added to the nomenclature, similar to the P-Metric system.

5. ISO Metric Sizing System The International Standards Organization (ISO) Metric system combines the Metric system with a service description. The service description provides the load index along with the speed rating symbol.

6. Millimetric Sizing System The Millimetric sizing system is similar to the Metric system except that the rim diameter is also represented in millimetres.

7. Light Truck Numeric System

Similar to the Numeric system for cars, it lists the section width in inches, construction type, rim diameter in inches, plus the light truck designation.

8. Light Truck Metric System

Similar to the P-Metric system, except the P is replaced with the LT light truck designation. Also, LT-Metric and P-Metric tyres differ in construction.

9. Light Truck High Flotation System

Similar to the Numeric system for cars, it lists the section width in inches, construction type, rim diameter in inches, plus the light truck designation.

Other Markings DOT Codes - Coding satisfying the requirements of the US Department of Transportation contain a mixture of letters and numbers such as DOT DVDE MTA 129. E-Marks - Tyres for sale in the European Community must carry an E -Mark in accordance with ECE Reg 30 - eg E4 027550.

Aspect Ratio (or sidewall height) Aspect ratio is the ratio of a tyre's width to it's height. A 70 series tyre, therefore, is a tyre whose height is equal to 70% of its width. Lower Profile Tyres hence have lower series numbers.

Speed Ratings All tyres carry a speed symbol in the form of a letter indicating the maximum speed for

which the tyre is intended. This indicates the maximum speed that the tyre can sustain for a ten minute endurance without coming to pieces and destroying itself and the car it is on. The table below shows which speed goes with each letter : Speed Category Symbol D E F G J K L M N P

Speed (km/h)

Speed Category Symbol Q R S T U H V W Y ZR

65 70 80 90 100 110 120 130 140 150

Speed (km/h) 160 170 180 190 200 210 240 270 300 * OVER 240

Load Indices The load-index figure imprinted on the sidewall of the tyre denotes the maximum load capacity of a tyre when driven at maximum speed. A list of load indices and maximum weights is give below : L I

K g

L I

K g

L I

K g

L I

K g

L I

Kg

L I

Kg

L I

Kg

0

4 5

4 0

1 4 0

8 0

4 5 0

1 2 0

1 4 0 0

1 6 0

45 00

2 0 0

14 00 0

2 4 0

450 00

1

4 6. 2

4 1

1 4 5

8 1

4 6 2

1 2 1

1 4 5 0

1 6 1

46 25

2 0 1

14 50 0

2 4 1

462 50

2

4 7. 5

4 2

1 5 0

8 2

4 7 5

1 2 2

1 5 0 0

1 6 2

47 50

2 0 2

15 00 0

2 4 2

475 00

3

4 8. 7

4 3

1 5 5

8 3

4 8 7

1 2 3

1 5 5 0

1 6 3

48 75

2 0 3

15 50 0

2 4 3

487 50

4

5 0

4 4

1 6 0

8 4

5 0 0

1 2 4

1 6 0 0

1 6 4

50 00

2 0 4

16 00 0

2 4 4

500 00

5

5 1. 5

4 5

1 6 5

8 5

5 1 5

1 2 5

1 6 5 0

1 6 5

51 50

2 0 5

16 50 0

2 4 5

515 00

6

5 3

4 6

1 7 0

8 6

5 3 0

1 2 6

1 7 0 0

1 6 6

53 00

2 0 6

17 00 0

2 4 6

530 00

7

5 4. 5

4 7

1 7 5

8 7

5 4 5

1 2 7

1 7 5 0

1 6 7

54 50

2 0 7

17 50 0

2 4 7

545 00

8

5 6

4 8

1 8 0

8 8

5 6 0

1 2 8

1 8 0 0

1 6 8

56 00

2 0 8

18 00 0

2 4 8

560 00

9

5 8

4 9

1 8 5

8 9

5 8 0

1 2 9

1 8 5 0

1 6 9

58 00

2 0 9

18 50 0

2 4 9

580 00

1 0

6 0

5 0

1 9 0

9 0

6 0 0

1 3 0

1 9 0 0

1 7 0

60 00

2 1 0

19 00 0

2 5 0

600 00

1 1

6 1. 5

5 1

1 9 5

9 1

6 1 5

1 3 1

1 9 5 0

1 7 1

61 50

2 1 1

19 50 0

2 5 1

615 00

1 2

6 3

5 2

2 0 0

9 2

6 3 0

1 3 2

2 0 0 0

1 7 2

63 00

2 1 2

20 00 0

2 5 2

630 00

1 3

6 5

5 3

2 0

9 3

6 5

1 3

2 0

1 7

65 00

2 1

20 60

2 5

650 00

6

0

3

6 0

3

3

0

3

1 4

6 7

5 4

2 1 2

9 4

6 7 0

1 3 4

2 1 2 0

1 7 4

67 00

2 1 4

21 20 0

2 5 4

670 00

1 5

6 9

5 5

2 1 8

9 5

6 9 0

1 3 5

2 1 8 0

1 7 5

69 00

2 1 5

21 80 0

2 5 5

690 00

1 6

7 1

5 6

2 2 4

9 6

7 1 0

1 3 6

2 2 4 0

1 7 6

71 00

2 1 6

22 40 0

2 5 6

710 00

1 7

7 3

5 7

2 3 0

9 7

7 3 0

1 3 7

2 3 0 0

1 7 7

73 00

2 1 7

23 00 0

2 5 7

730 00

1 8

7 5

5 8

2 3 6

9 8

7 5 0

1 3 8

2 3 6 0

1 7 8

75 00

2 1 8

23 60 0

2 5 8

750 00

1 9

7 7. 5

5 9

2 4 3

9 9

7 7 5

1 3 9

2 4 3 0

1 7 9

77 50

2 1 9

24 30 0

2 5 9

775 00

2 0

8 0

6 0

2 5 0

1 0 0

8 0 0

1 4 0

2 5 0 0

1 8 0

80 00

2 2 0

25 00 0

2 6 0

800 00

2 1

8 2. 5

6 1

2 5 7

1 0 1

8 2 5

1 4 1

2 5 7 5

1 8 1

82 50

2 2 1

25 75 0

2 6 1

825 00

2 2

8 5

6 2

2 6 5

1 0 2

8 5 0

1 4 2

2 6 5 0

1 8 2

85 00

2 2 2

26 50 0

2 6 2

850 00

2 3

8 7. 5

6 3

2 7 2

1 0 3

8 7 5

1 4 3

2 7 2 5

1 8 3

87 50

2 2 3

27 25 0

2 6 3

875 00

2 4

9 0

6 4

2 8 0

1 0 4

9 0 0

1 4 4

2 8 0 0

1 8 4

90 00

2 2 4

28 00 0

2 6 4

900 00

2 5

9 2. 5

6 5

2 9 0

1 0 5

9 2 5

1 4 5

2 9 0 0

1 8 5

92 50

2 2 5

29 00 0

2 6 5

925 00

2 6

9 5

6 6

3 0 0

1 0 6

9 5 0

1 4 6

3 0 0 0

1 8 6

95 00

2 2 6

30 00 0

2 6 6

950 00

2 7

9 7. 5

6 7

3 0 7

1 0 7

9 7 5

1 4 7

3 0 7 5

1 8 7

97 50

2 2 7

30 75 0

2 6 7

975 00

2 8

1 0 0

6 8

3 1 5

1 0 8

1 0 0 0

1 4 8

3 1 5 0

1 8 8

10 00 0

2 2 8

31 50 0

2 6 8

100 000

2 9

1 0 3

6 9

3 2 5

1 0 9

1 0 3 0

1 4 9

3 2 5 0

1 8 9

10 30 0

2 2 9

32 50 0

2 6 9

103 000

3 0

1 0 6

7 0

3 3 5

1 1 0

1 0 6 0

1 5 0

3 3 5 0

1 9 0

10 60 0

2 3 0

33 50 0

2 7 0

106 000

3 1

1 0 9

7 1

3 4 5

1 1 1

1 0 9 0

1 5 1

3 4 5 0

1 9 1

10 90 0

2 3 1

34 50 0

2 7 1

109 000

3 2

1 1 2

7 2

3 5 5

1 1 2

1 1 2 0

1 5 2

3 5 5 0

1 9 2

11 20 0

2 3 2

35 50 0

2 7 2

112 000

3 3

1 1 5

7 3

3 6 5

1 1 3

1 1 5 0

1 5 3

3 6 5 0

1 9 3

11 50 0

2 3 3

36 50 0

2 7 3

115 000

3 4

1 1

7 4

3 7

1 1

1 1

1 5

3 7

1 9

11 80

2 3

37 50

2 7

118 000

8

5

4

8 0

4

5 0

4

0

4

0

4

3 5

1 2 1

7 5

3 8 7

1 1 5

1 2 1 5

1 5 5

3 8 7 5

1 9 5

12 15 0

2 3 5

38 75 0

2 7 5

121 000

3 6

1 2 5

7 6

4 0 0

1 1 6

1 2 5 0

1 5 6

4 0 0 0

1 9 6

12 50 0

2 3 6

40 00 0

2 7 6

125 000

3 7

1 2 8

7 7

4 1 2

1 1 7

1 2 8 5

1 5 7

4 1 2 5

1 9 7

12 85 0

2 3 7

41 25 0

2 7 7

128 500

3 8

1 3 2

7 8

4 2 5

1 1 8

1 3 2 0

1 5 8

4 2 5 0

1 9 8

13 20 0

2 3 8

42 50 0

2 7 8

132 000

4 3 7

1 1 9

1 9 9

13 60 0

2 3 9

43 75 0

2 7 9

3 9

1 3 6

7 9

1 3 6 0

1 5 9

4 3 7 5

136 000

Provided here, for your benefit, are simple definitions of technical tyre terms that will enable you to understand the technology that goes into a tyre. Learn what each part of a tyre does, and get tyre-savvy!

Tyre Placard

Decoding all that information on the sidewall Tyre Sizing Systems Other Markings Aspect Ratio (or sidewall height) Speed Ratings Load Indices

Tyre Placard

1. A vehicle's original tyre and wheel specifications are detailed on a placard affixed to all vehicles manufactured on or after the 1st of January 1973.

2. The tyres conform to specific load carrying specifications as recommended on the vehicle manufacturer's tyre placard, as required by Australian Design Rule 23 (ADR23).

3. Tyres should be appropriate to the type and size of rim fitted to the vehicle.

Decoding all that information on the sidewall All numbers, letters, symbols, mysterious codes. Here's the important stuff: A : Manufacturer or brand name, and commercial name or identity. B & J : Tyre size, construction and speed rating designations. See tyre sizes and speed ratings below. C : Denotes type of tyre construction. D : M&S denotes a tyre designed for mud and snow. Reinforced marking only where applicable. E : Load and pressure marking requirement.

Tyre Sizing Systems Over the years there has been many different methods used to size tyres. Many of these are still in use today, with the ISO Metric Sizing System the most widely used.

1. Numeric Sizing System This first system developed for tyre sizing was used until the late 1960s, but provided only the cross section width of the tyre and the rim diameter in inches. If the section width ended in zero (e.g., 7.00-14 or 7.50-14), the tyre had a common aspect ratio of about 92. For section widths not ending in zero (e.g., 8.25-15), the tyre was considered "low profile" with an aspect ratio of about 82.

2. Alphanumeric Sizing System

In 1968, a new concept was introduced worldwide. The Alphanumeric sizing system is a load-based system where tyres are designated by their load-carrying capacity and aspect ratio. The first letter is the load and size relationship, with letters ranging from A to N. The lower the letter, the smaller the size and, of course, the lower the load-carrying capacity of the tyre.

3. P-Metric Sizing System To accommodate the smaller tyres used on compact cars, the P-Metric (Passenger Metric) system was created in 1976. The maximum inflation pressures of P-Metric tyres were raised for lower rolling resistance.

4. Metric Sizing System

Because Europe primarily uses the metric system of measurement; the Metric sizing system was developed. It is essentially a conversion of the Numeric system. Section widths are notated in millimetres instead of inches. Originally, tyres not identified with an aspect ratio were assumed to be 82-series. When 60- and 70 series tyres appeared, the aspect ratio was added to the nomenclature, similar to the P-Metric system.

5. ISO Metric Sizing System The International Standards Organization (ISO) Metric system combines the Metric system with a service description. The service description provides the load index along with the speed rating symbol.

6. Millimetric Sizing System The Millimetric sizing system is similar to the Metric system except that the rim diameter is also represented in millimetres.

7. Light Truck Numeric System

Similar to the Numeric system for cars, it lists the section width in inches, construction type, rim diameter in inches, plus the light truck designation.

8. Light Truck Metric System

Similar to the P-Metric system, except the P is replaced with the LT light truck designation. Also, LT-Metric and P-Metric tyres differ in construction.

9. Light Truck High Flotation System

Similar to the Numeric system for cars, it lists the section width in inches, construction type, rim diameter in inches, plus the light truck designation.

Other Markings DOT Codes - Coding satisfying the requirements of the US Department of Transportation contain a mixture of letters and numbers such as DOT DVDE MTA 129. E-Marks - Tyres for sale in the European Community must carry an E -Mark in accordance with ECE Reg 30 - eg E4 027550.

Aspect Ratio (or sidewall height) Aspect ratio is the ratio of a tyre's width to it's height. A 70 series tyre, therefore, is a tyre whose height is equal to 70% of its width. Lower Profile Tyres hence have lower series numbers.

Speed Ratings All tyres carry a speed symbol in the form of a letter indicating the maximum speed for

which the tyre is intended. This indicates the maximum speed that the tyre can sustain for a ten minute endurance without coming to pieces and destroying itself and the car it is on. The table below shows which speed goes with each letter : Speed Category Symbol D E F G J K L M N P

Speed (km/h)

Speed Category Symbol Q R S T U H V W Y ZR

65 70 80 90 100 110 120 130 140 150

Speed (km/h) 160 170 180 190 200 210 240 270 300 * OVER 240

Load Indices The load-index figure imprinted on the sidewall of the tyre denotes the maximum load capacity of a tyre when driven at maximum speed. A list of load indices and maximum weights is give below : L I

K g

L I

K g

L I

K g

L I

K g

L I

Kg

L I

Kg

L I

Kg

0

4 5

4 0

1 4 0

8 0

4 5 0

1 2 0

1 4 0 0

1 6 0

45 00

2 0 0

14 00 0

2 4 0

450 00

1

4 6. 2

4 1

1 4 5

8 1

4 6 2

1 2 1

1 4 5 0

1 6 1

46 25

2 0 1

14 50 0

2 4 1

462 50

2

4 7. 5

4 2

1 5 0

8 2

4 7 5

1 2 2

1 5 0 0

1 6 2

47 50

2 0 2

15 00 0

2 4 2

475 00

3

4 8. 7

4 3

1 5 5

8 3

4 8 7

1 2 3

1 5 5 0

1 6 3

48 75

2 0 3

15 50 0

2 4 3

487 50

4

5 0

4 4

1 6 0

8 4

5 0 0

1 2 4

1 6 0 0

1 6 4

50 00

2 0 4

16 00 0

2 4 4

500 00

5

5 1. 5

4 5

1 6 5

8 5

5 1 5

1 2 5

1 6 5 0

1 6 5

51 50

2 0 5

16 50 0

2 4 5

515 00

6

5 3

4 6

1 7 0

8 6

5 3 0

1 2 6

1 7 0 0

1 6 6

53 00

2 0 6

17 00 0

2 4 6

530 00

7

5 4. 5

4 7

1 7 5

8 7

5 4 5

1 2 7

1 7 5 0

1 6 7

54 50

2 0 7

17 50 0

2 4 7

545 00

8

5 6

4 8

1 8 0

8 8

5 6 0

1 2 8

1 8 0 0

1 6 8

56 00

2 0 8

18 00 0

2 4 8

560 00

9

5 8

4 9

1 8 5

8 9

5 8 0

1 2 9

1 8 5 0

1 6 9

58 00

2 0 9

18 50 0

2 4 9

580 00

1 0

6 0

5 0

1 9 0

9 0

6 0 0

1 3 0

1 9 0 0

1 7 0

60 00

2 1 0

19 00 0

2 5 0

600 00

1 1

6 1. 5

5 1

1 9 5

9 1

6 1 5

1 3 1

1 9 5 0

1 7 1

61 50

2 1 1

19 50 0

2 5 1

615 00

1 2

6 3

5 2

2 0 0

9 2

6 3 0

1 3 2

2 0 0 0

1 7 2

63 00

2 1 2

20 00 0

2 5 2

630 00

1 3

6 5

5 3

2 0

9 3

6 5

1 3

2 0

1 7

65 00

2 1

20 60

2 5

650 00

6

0

3

6 0

3

3

0

3

1 4

6 7

5 4

2 1 2

9 4

6 7 0

1 3 4

2 1 2 0

1 7 4

67 00

2 1 4

21 20 0

2 5 4

670 00

1 5

6 9

5 5

2 1 8

9 5

6 9 0

1 3 5

2 1 8 0

1 7 5

69 00

2 1 5

21 80 0

2 5 5

690 00

1 6

7 1

5 6

2 2 4

9 6

7 1 0

1 3 6

2 2 4 0

1 7 6

71 00

2 1 6

22 40 0

2 5 6

710 00

1 7

7 3

5 7

2 3 0

9 7

7 3 0

1 3 7

2 3 0 0

1 7 7

73 00

2 1 7

23 00 0

2 5 7

730 00

1 8

7 5

5 8

2 3 6

9 8

7 5 0

1 3 8

2 3 6 0

1 7 8

75 00

2 1 8

23 60 0

2 5 8

750 00

1 9

7 7. 5

5 9

2 4 3

9 9

7 7 5

1 3 9

2 4 3 0

1 7 9

77 50

2 1 9

24 30 0

2 5 9

775 00

2 0

8 0

6 0

2 5 0

1 0 0

8 0 0

1 4 0

2 5 0 0

1 8 0

80 00

2 2 0

25 00 0

2 6 0

800 00

2 1

8 2. 5

6 1

2 5 7

1 0 1

8 2 5

1 4 1

2 5 7 5

1 8 1

82 50

2 2 1

25 75 0

2 6 1

825 00

2 2

8 5

6 2

2 6 5

1 0 2

8 5 0

1 4 2

2 6 5 0

1 8 2

85 00

2 2 2

26 50 0

2 6 2

850 00

2 3

8 7. 5

6 3

2 7 2

1 0 3

8 7 5

1 4 3

2 7 2 5

1 8 3

87 50

2 2 3

27 25 0

2 6 3

875 00

2 4

9 0

6 4

2 8 0

1 0 4

9 0 0

1 4 4

2 8 0 0

1 8 4

90 00

2 2 4

28 00 0

2 6 4

900 00

2 5

9 2. 5

6 5

2 9 0

1 0 5

9 2 5

1 4 5

2 9 0 0

1 8 5

92 50

2 2 5

29 00 0

2 6 5

925 00

2 6

9 5

6 6

3 0 0

1 0 6

9 5 0

1 4 6

3 0 0 0

1 8 6

95 00

2 2 6

30 00 0

2 6 6

950 00

2 7

9 7. 5

6 7

3 0 7

1 0 7

9 7 5

1 4 7

3 0 7 5

1 8 7

97 50

2 2 7

30 75 0

2 6 7

975 00

2 8

1 0 0

6 8

3 1 5

1 0 8

1 0 0 0

1 4 8

3 1 5 0

1 8 8

10 00 0

2 2 8

31 50 0

2 6 8

100 000

2 9

1 0 3

6 9

3 2 5

1 0 9

1 0 3 0

1 4 9

3 2 5 0

1 8 9

10 30 0

2 2 9

32 50 0

2 6 9

103 000

3 0

1 0 6

7 0

3 3 5

1 1 0

1 0 6 0

1 5 0

3 3 5 0

1 9 0

10 60 0

2 3 0

33 50 0

2 7 0

106 000

3 1

1 0 9

7 1

3 4 5

1 1 1

1 0 9 0

1 5 1

3 4 5 0

1 9 1

10 90 0

2 3 1

34 50 0

2 7 1

109 000

3 2

1 1 2

7 2

3 5 5

1 1 2

1 1 2 0

1 5 2

3 5 5 0

1 9 2

11 20 0

2 3 2

35 50 0

2 7 2

112 000

3 3

1 1 5

7 3

3 6 5

1 1 3

1 1 5 0

1 5 3

3 6 5 0

1 9 3

11 50 0

2 3 3

36 50 0

2 7 3

115 000

3 4

1 1

7 4

3 7

1 1

1 1

1 5

3 7

1 9

11 80

2 3

37 50

2 7

118 000

8

5

4

8 0

4

5 0

4

0

4

0

4

3 5

1 2 1

7 5

3 8 7

1 1 5

1 2 1 5

1 5 5

3 8 7 5

1 9 5

12 15 0

2 3 5

38 75 0

2 7 5

121 000

3 6

1 2 5

7 6

4 0 0

1 1 6

1 2 5 0

1 5 6

4 0 0 0

1 9 6

12 50 0

2 3 6

40 00 0

2 7 6

125 000

3 7

1 2 8

7 7

4 1 2

1 1 7

1 2 8 5

1 5 7

4 1 2 5

1 9 7

12 85 0

2 3 7

41 25 0

2 7 7

128 500

3 8

1 3 2

7 8

4 2 5

1 1 8

1 3 2 0

1 5 8

4 2 5 0

1 9 8

13 20 0

2 3 8

42 50 0

2 7 8

132 000

3 9

1 3 6

7 9

4 3 7

1 1 9

1 3 6 0

1 5 9

4 3 7 5

1 9 9

13 60 0

2 3 9

43 75 0

2 7 9

136 000

Passenger Car Tyre

• • • • • •

Ultima-XPS Tornado Rally Ultima Sport Ultima Royale Vectra

LCV Tyre

• • • •

Steel King Brute 4x4 Brute_LT Elanzo

LCV/Truck Tyre

•

Jetsteel JDH

Error proof Computer Aided Design & Analysis

We design tyres for your vehicles using the latest tools & techniques which enable us to judge and eliminate chances of failure at the drawing board stage only.

World class manufacturing on Automatic Machines

Your Radials are manufactured in an air conditioned plant equipped with the finest machines

so that you get consistently good quality.

Rigorous Testing

Before JK Tyre comes to you, it has to pass tough validation tests, both indoor as well as outdoor. JK Tyre is one of the few companies that test their tyres so rigorously.