Dimension Designation For Tyre - Volvo XC40 TWIN ENGINE 2019 Owner's Manual

WHEELS AND TYRES

Dimension designation for tyre

Designations for tyre dimension, load index
and speed rating.
The car has an approval for the complete vehi-
cle with certain combinations of wheel rims
and tyres.
Designation of dimensions
All tyres have a dimension designation, such
as: 235/50 R19 99 V.
235 Tyre width (mm)
50 Ratio between tyre wall height and
tyre width (%)
R Radial ply
19 Rim diameter in inches
99 Codes for the maximum permitted
tyre load, tyre load index (LI)
V Speed rating for maximum permitted
speed, speed rating (SS). (In this
case 240 km/h (149 mph).)
Load index
Each tyre has a certain capacity to carry a
load, a load index (LI). The car's weight deter-
mines the load capacity required of the tyres.
2 Both those with metal studs and those without.
538
Speed rating
Each tyre can withstand a certain maximum
speed. Tyre speed rating, SS (Speed Symbol),
must at least correspond with the car's top
speed. The table below shows the maximum
permitted speed for each speed rating (SS).
The only exception to these regulations is win-
2
ter tyres , where a lower speed rating may be
used. If such a tyre is selected, the car must
not be driven more quickly than the tyre is
rated for. For example, cars with Q rating tyres
must be driven at speeds not exceeding
160 km/h (100 mph). The road conditions and
applicable road traffic rules determine how
quickly the car can be driven, not the speed
rating of the tyres.
NOTE
The maximum permitted speed is specified
in the table.
Q 160 km/h (100 mph) (used only on
winter tyres)
T 190 km/h (118 mph)
H 210 km/h (130 mph)
V 240 km/h (149 mph)
W 270 km/h (168 mph)
Y 300 km/h (186 mph)
WARNING
The lowest permitted tyre load index (LI)
and speed rating (SS) for the tyres for each
respective engine variant are shown in the
specifications, which can be found in the
printed owner's manual. If a tyre with too
low a load index or speed rating is used, it
may overheat and be damaged.
Related information
Tyres (p. 536)
•
Dimension designation for wheel rim
•
(p. 539)
Approved wheel and tyre sizes (p. 649)
•
Minimum permitted tyre load index and
•
speed rating for tyres (p. 650)