height CADILLAC ATS 2013 1.G User Guide

Black plate (47,1)Cadillac ATS Owner Manual - 2013 - CRC - 10/5/12
Vehicle Care 10-47
Tire Designations
Tire Size
The following is an example of a
typical passenger vehicle
tire size.
(1) Passenger (P-Metric) Tire:
The United States version of a
metric tire sizing system. The
letter P as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire
and Rim Association.
(2) Tire Width
:The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall. (3) Aspect Ratio
:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 60, as shown in
item 3 of the illustration, it would
mean that the tire's sidewall is
60 percent as high as it is wide.
(4) Construction Code
: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
construction; and the letter B
means belted-bias ply
construction.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Service Description
:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples
of optional accessories are
automatic transmission, power
steering, power brakes, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.

Black plate (64,1)Cadillac ATS Owner Manual - 2013 - CRC - 10/5/12
10-64 Vehicle Care
{WARNING
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing
a crash. Always use the correct
wheel, wheel bolts, and wheel
nuts for replacement.
Notice: The wrong wheel can
also cause problems with bearing
life, brake cooling, speedometer
or odometer calibration,
headlamp aim, bumper height,
vehicle ground clearance, and tire
clearance to the body and
chassis.
{WARNING
Rust or dirt on a wheel, or on
the parts to which it is
fastened, can make wheel
nuts become loose after a
time. The wheel could come
off and cause a crash. When
changing a wheel, remove any
rust or dirt from places where
the wheel attaches to the
vehicle. In an emergency, a
cloth or a paper towel can be
used, however, use a scraper
or wire brush to remove all
rust or dirt.
{WARNING
Never use oil or grease on studs
or the threads of the wheel nuts.
The wheel nuts might come loose
and the wheel could fall off,
causing a crash.
{WARNING
Incorrect wheel nuts or improperly
tightened wheel nuts can cause
the wheel to become loose and
even come off. This could lead to
a crash. Be sure to use the
correct wheel nuts. If you have to
replace them, be sure to get new
GM original equipment
wheel nuts.
Notice: Improperly tightened
wheel nuts can lead to brake
pulsation and rotor damage. To
avoid expensive brake repairs,
evenly tighten the wheel nuts in
the proper sequence and to the
proper torque specification.