Saab 3-Sep Automobile User Manual


 
239Car care
Aspect ratio: A two-digit number that indi-
cates the tire height-to-width measure-
ments. For example, if the tire size aspect
ratio is “55”, as shown in item “C” of the illus-
tration, it would mean that the tire´s sidewall
is 55% as high as it is wide.
Belt Rating: A letter code is used to indicate
the type of ply construction in the tire. The
letter “R” means radial ply construction; the
letter “D” means diagonal or bias ply con-
struction; and the letter “B” means belted-
bias ply construction.
Rim Diameter: Diameter of the wheel in
inches.
Load range: The load range represents the
load carry capacity a tire is certified to carry.
Speed Rating: The maximum speed that a
tire is certified to carry a load. Speed ratings
range from “A” to “Z”.
Tire markings
An example of the meaning of the different
markings in a tire size is given below for a
tire size of 225/45 R17 94H:
225 Tire section width, mm
45 Aspect ratio, i.e. the section height
as a percentage of the section
width
R Radial ply
17 Wheel rim diameter 15 in at bead
seats
94 Tire load index
H Speed rating
Tire load indices
91 Tire approved for max. 1355 lbs.
(615 kg)
93 Max. 1433 lbs. (650 kg)
94 Max. 1477 lbs. (670 kg)
Speed ratings
S Tire approved for speeds up to
110 mph (180 km/h)
T Max. 118 mph (190 km/h)
H Max. 130 mph (210 km/h)
V Max. 149 mph (240 km/h)
W Max. 168 mph (270 km/h)
Y Max. 186 mph (300 km/h)
TIN-code
a Manufacturer´s Identification Mark
b Tire Size
c Tire Type Code
d Date of Manufacture