Buick LaCrosse Owner's Manual page 386

Consider installing winter tires on
the vehicle if frequent driving on
snow or ice covered roads is
expected. All season tires provide
good overall performance on most
surfaces, but they may not offer the
traction or the same level of
performance as winter tires on snow
or ice covered roads.
Winter tires, in general, are
designed for increased traction on
snow and ice covered roads. With
winter tires, there may be decreased
dry road traction, increased road
noise, and shorter tread life. After
changing to winter tires, be alert for
changes in vehicle handling and
braking.
See your dealer for details
regarding winter tire availability and
proper tire selection. Also, see
If using snow tires:
Use tires of the same brand and
tread type on all four wheel
positions.
Use only radial ply tires of the
same size, load range, and
speed rating as the original
equipment tires.
Winter tires with the same speed
rating as the original equipment tires
may not be available for H, V, W, Y,
and ZR speed rated tires. If winter
tires with a lower speed rating are
chosen, never exceed the tire's
maximum speed capability.
Useful information about a tire is
molded into its sidewall. The
examples show a typical
passenger vehicle tire and a
compact spare tire sidewall.
.
The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
Tire Size illustration later in this
section for more detail.