Understanding your Tyre and Basic Safety
In
the interest of the Discussion I was having with a colleague about tyres and
the pressure that needs to be maintained.
I
thought I might as well pen down my learning and pass it to the guys who would
like to know the same.
Article dedicated to my Hyundai i20
Past
studies have shown that simple tasks like maintaining proper tyre pressure,
driving within the load limits, basic tyre inspection for cuts and cracks or
irregularities are some of the most important things you can do which will
certainly go a long way in avoiding a tyre failure and resultant accidents.
These
activities carried out regularly, along with other activities will go a long
way in
1.
Improving the handling
2.
Avoid Breakdowns and Accidents
3.
Improve Fuel Efficiency
4.
Increase the life of your Tyres
1.
Temperature Resistance
2.
Traction
3.
Thread Wear
4.
Max Load Capacity
5.
Speed Symbol
6.
Manufacturing Date
Tyre Markings – Know Your Tyre
These letters indicates a tyre's resistance
to heat.
From highest to lowest, a tyre's resistance
to heat is graded as "A", "B", or "C".
|
Symbol
|
Area
|
|
A
|
Hot Area
|
|
B
|
Normal Area
|
|
B
|
Cold Area
|
This letter indicates a tyre's ability to
stop on wet pavement.
A higher graded tyre should allow you to stop
your car on wet roads in a shorter distance than a tyre with a lower grade.
Traction is graded from highest to lowest as
"AA","A", "B", and "C".
Traction Indicator
Number indicates the maximum load
that can be carried by the tyre.
Symbol indicates the maximum Speed at
which a tyre is designed to be driven for extended periods of time.
|
Code
|
km/h
|
Code
|
km/h
|
Code
|
km/h
|
Code
|
km/h
|
|
A1
|
5
|
B
|
50
|
L
|
120
|
U
|
200
|
|
A2
|
10
|
C
|
60
|
M
|
130
|
H
|
210
|
|
A3
|
15
|
D
|
65
|
N
|
140
|
V
|
240
|
|
A4
|
20
|
E
|
70
|
P
|
150
|
Z
|
over 240
|
|
A5
|
25
|
F
|
80
|
Q
|
160
|
W
|
270
|
|
A6
|
30
|
G
|
90
|
R
|
170
|
(W)
|
over 270
|
|
A7
|
35
|
J
|
100
|
S
|
180
|
Y
|
300
|
|
A8
|
40
|
K
|
110
|
T
|
190
|
(Y)
|
over
300
|
Speed
Indicator Chart
|
Code
|
Weight -Kgs
|
Code
|
Weight -Kgs
|
Code
|
Weight -Kgs
|
Code
|
Weight -Kgs
|
Code
|
Weight -Kgs
|
|
60
|
250
|
74
|
375
|
88
|
560
|
102
|
850
|
116
|
1,250
|
|
61
|
257
|
75
|
387
|
89
|
580
|
103
|
875
|
117
|
1,285
|
|
62
|
265
|
76
|
400
|
90
|
600
|
104
|
900
|
118
|
1,320
|
|
63
|
272
|
77
|
412
|
91
|
615
|
105
|
925
|
119
|
1,360
|
|
64
|
280
|
78
|
425
|
92
|
630
|
106
|
950
|
120
|
1,400
|
|
65
|
290
|
79
|
437
|
93
|
650
|
107
|
975
|
121
|
1,450
|
|
66
|
300
|
80
|
450
|
94
|
670
|
108
|
1,000
|
122
|
1,500
|
|
67
|
307
|
81
|
462
|
95
|
690
|
109
|
1,030
|
123
|
1,550
|
|
68
|
315
|
82
|
475
|
96
|
710
|
110
|
1,060
|
124
|
1,600
|
|
69
|
325
|
83
|
487
|
97
|
730
|
111
|
1,090
|
125
|
1,650
|
|
70
|
335
|
84
|
500
|
98
|
750
|
112
|
1,120
|
|
|
|
71
|
345
|
85
|
515
|
99
|
775
|
113
|
1,150
|
|
|
|
72
|
355
|
86
|
530
|
100
|
800
|
114
|
1,180
|
|
|
|
73
|
365
|
87
|
545
|
101
|
825
|
115
|
1,215
|
|
|
Load Carrying
Capacity Indicator
Tyres
carry a DOT number on the sidewall that gives a production date.
Since
the year 2000 the numbers consist of 4 digits instead of 3.
The
first two digits indicate the calendar week of production and the next two the
year of production.
Eg: 2413 – the
tyre was manufactured in the 24th week of 2013.
 |
For tyres
manufactured in the 1990's there is a little triangle ∆ after the DOT code. Eg:
4 2 8 ∆ - the tyre was manufactured in the 42nd week of 1998.
Ensure Proper Tyre Pressure. Just looking at the tyre’s
wouldn’t suffice, your eyes might deceive you.
Rely on a proper Gauge to check tyre pressure.
Tip: Ensure you check
the air pressure every time you fill fuel. Any slight pull to either side, is
an indicator of tyres not being at their optimum pressure.
Tyre wear is uneven for any number of reasons. Even tyre wear is desirable to maintain consistent performance in the vehicle and to extend the overall life of a set of tyres.
Tyre
Rotation Pattern
By design, the weight on the front and rear axles differs which causes uneven wear
With the majority of cars being front-engine cars,
·
The front
axle typically bears more of the weight.
·
Front wheel
drive vehicles also have the differential in front, adding to the weight, with
a typical weight distribution of no better than 60:40
·
This means,
all else being equal, the front tyres wear out at almost twice the rate of the
rear wheels, especially when factoring the additional stress that braking puts
on the front tyres
Thus, tyre rotation needs to
occur more frequently for front-wheel drive vehicles.For rear wheel drive vehicles, the weight distribution between front and back approaches 50:50.
Always check for Tyre Wear and Thread Depth. You can easily do a visual check which is also called the 1 Rupee Coin Test
Illustrated below in the diagram.
Insert the coin between the threads, and if the Rupaih in hindi is hidden, you are good to go, else if its visible, its Time to Change the Tyre.
Never go in for Re-Threaded Tyres
3 Golden Rules
1.
Inflate
a.
Check your tyre pressure
Regularly
2.
Rotate
a.
Rotate the tyres every 8000kms
3.
Inspect
a.
Routinely look for signs of
Damage and Thread Wear
