The load capacity of the tyre shown as an index. which should be looked up on the load index scale table here. In this case the load capacity of the tyre at the correct inflation pressure is 710kg.
The speed symbol, i.e. the maximum sustainable speed for the tyre at the load capacity given - in this case 186.4mph. View the Speed Table below
SPEED SYMBOL GUIDE (NORMAL USE)
SYMBOL
kph
mph
CAR
S
180
111.8
T
190
118.1
U
200
124.3
H
210
130.5
V
240
149.1
W
270
167.8
Y
300
186.4
VR*
210+
130+
ZR*
240+
150+
WINTER/REINFORCED
Q
160
99.4
R
170
105.6
VAN
N
140
87
P
150
93.2
TRUCK
J
100
62.1
K
110
68.4
L
120
74.6
M
130
80.8
*Old designation
TUBELESSHide The tubeless tyres are safer than tubed tyres when it comes to punctures in the tread region. In the event of a nail hole or other small penetrations in the tread region, the air leakage is very slow and sometimes, not at all, as the rubber may make a seal around the penetrating object. In fact, on many occasions we have had nails and other foreign objects lodged in the tubeless tyres of our own personal cars and bikes and we have motored to safety and on to the tyrewallah to get it repaired in comfort.
In place of the tube in a normal tyre, the tyre and the rim of the wheel form an air container in a tubeless tyre. To 'seal in the air', in this tyre-rim compartment, the inner wall of the tyre is throughly lined with an impermeable, air-tight membrane. The inner liner of the tubeless tyre is constructed of halo-butyl/chlorobutyl and other materials. This performs, in essence, the important chore of substantially reducing the permeation of air, as compared to the natural rubber inner liner, a function of which is why we use a butyl tube in a tubed tyre.
A tubeless tyre also comes with a soft rubber chaffer, distinct from a rubberised fabric chaffer in a tubed tyre. This works as an all-round air seal between the tyre and rim.
As there is no tube, and, hence, no tube valve, a specialised valve is employed for increasing/reducing the air pressure in a tubeless tyre. The valve (check out the line drawing to see how it mounts) sits on the tyre rim and is ingeniously sealed by a large high quality rubber seal which is easy to mount.
As with the letter "R", this refers to the tyres construction. "Steel Belted" is a particular form of radial construction.
Radial tires lay all of the cord plies at 90 degrees to the direction of travel (that is, across the tire from lip to lip). This design avoids having the plies rub against each other as the tire flexes, reducing the rolling friction of the tire.
This allows vehicles with radial tires to achieve better fuel economy than vehicles with bias-ply tires. It also accounts for the slightly "low on air" (bulging) look that radial tire sidewalls have, especially when compared to bias-ply tires.
Interestingly the steel wire in radial car tires becomes magnetic so that when the tire rotates you get an alternating magnetic field. It is quite measurable with an EMF meter close to the wheel well when the car is moving and is a spectrum of harmonic strengths from 10 to several hundred Hertz.
The type approval mark of the American Department of Transport, showing that our tyres have passed their strict testing procedures. When a tyre has passed both the American and European test programmes, you know you can have complete faith in it.
