2015 BUICK REGAL wheel size

Black plate (28,1)Buick Regal Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7576024) - 2015 - CRC - 9/15/14
3-28 Seats and Restraints
{Warning
For up to 10 seconds after the
vehicle is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet
metal, may keep the airbag system
from working properly. The
operation of the airbag system can
also be affected by changing any
parts of the front seats, safety belts,
the airbag sensing and diagnosticmodule, steering wheel, instrument
panel, any of the airbag modules,
ceiling or pillar garnish trim, front
sensors, side impact sensors,
or airbag wiring.
Your dealer and the service manual
have information about the location
of the airbag sensors, sensing and
diagnostic module, and airbag
wiring.
In addition, the vehicle has a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger seat. The
passenger sensing system may not
operate properly if the original seat
trim is replaced with non-GM
covers, upholstery, or trim; or with
GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad
or device, installed under or on top
of the seat fabric, could also
interfere with the operation of the
passenger sensing system. This
could either prevent properdeployment of the passenger
airbag(s) or prevent the passenger
sensing system from properly
turning off the passenger airbag(s).
See
Passenger Sensing System on
page 3-23.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels on page 10-58 for
additional important information.
If you have to modify your vehicle
because you have a disability and
you have questions about whether
the modifications will affect the
vehicle's airbag system, or if you
have questions about whether the
airbag system will be affected if the
vehicle is modified for any other
reason, call Customer Assistance.
See Customer Assistance Offices
on page 13-3.

Black plate (31,1)Buick Regal Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7576024) - 2015 - CRC - 9/15/14
Driving and Operating 9-31
Drive Systems
All-Wheel Drive
If equipped, this feature transfers
torque to the rear wheels as
required. It is fully automatic, and
adjusts itself as needed for road
conditions.
All-Wheel Drive (AWD) performance
is automatically reduced when you
use the compact spare. To restore
full AWD performance, and prevent
excessive wear to the clutch in the
AWD system, replace the compact
spare tire with a full-size tire as
soon as possible. SeeCompact
Spare Tire on page 10-76.
Brakes
Antilock Brake
System (ABS)
This vehicle has ABS, an advanced
electronic braking system that helps
prevent a braking skid.
When the vehicle begins to drive
away, ABS checks itself.
A momentary motor or clicking noise
might be heard while this test is
going on, and it might even be
noticed that the brake pedal moves
a little. This is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
on page 5-24. If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses the wheels are
slowing down. If one of the wheels
is about to stop rolling, the computer
will separately work the brakes at
each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
you steer around the obstacle while
braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle

Black plate (2,1)Buick Regal Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7576024) - 2015 - CRC - 9/15/14
10-2 Vehicle Care
Tire Pressure for High-SpeedOperation . . . . . . . . . . . . . . . . . 10-50
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-50
Tire Pressure Monitor
Operation . . . . . . . . . . . . . . . . . 10-51
Tire Inspection . . . . . . . . . . . . . . 10-54
Tire Rotation . . . . . . . . . . . . . . . 10-55
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . 10-56
Buying New Tires . . . . . . . . . . . 10-57
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . 10-58
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . 10-59
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . 10-60
Wheel Replacement . . . . . . . . 10-61
Tire Chains . . . . . . . . . . . . . . . . . 10-61
If a Tire Goes Flat . . . . . . . . . . 10-62
Tire Sealant and Compressor Kit . . . . . . . . . . . 10-64
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . 10-71
Tire Changing . . . . . . . . . . . . . . 10-71
Compact Spare Tire . . . . . . . . 10-76Jump Starting
Jump Starting (On-board with eAssist Only) . . . . . . . . . 10-77
Jump Starting (with or without eAssist) . . . . . . . . . . . 10-78
Towing
Towing the Vehicle . . . . . . . . . 10-81
Recreational VehicleTowing . . . . . . . . . . . . . . . . . . . . 10-82
Appearance Care
Exterior Care . . . . . . . . . . . . . . . 10-85
Interior Care . . . . . . . . . . . . . . . . 10-89
Floor Mats . . . . . . . . . . . . . . . . . . 10-93
General Information
For service and parts needs, visit
your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks:
California Proposition
65 Warning
Most motor vehicles, including this
one, contain and/or emit chemicals
known to the State of California to

Black plate (42,1)Buick Regal Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7576024) - 2015 - CRC - 9/15/14
10-42 Vehicle Care
traction or performance as winter
tires on snow or ice-covered roads.
SeeWinter Tires on page 10-42.
Winter Tires
This vehicle was not originally
equipped with winter tires. Winter
tires are designed for increased
traction on snow and ice-covered
roads. Consider installing winter
tires on the vehicle if frequent
driving on ice or snow covered
roads is expected. See your dealer
for details regarding winter tire
availability and proper tire selection.
Also, see Buying New Tires on
page 10-57.
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.
If using winter 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.
Summer Tires
This vehicle may come with high
performance summer tires. These
tires have a special tread and
compound that are optimized for
maximum dry and wet road
performance. This special tread and
compound will have decreased
performance in cold climates, and
on ice and snow. We recommend
installing winter tires on the vehicle
if frequent driving at temperatures
below approximately 5°C (40°F) or
on ice or snow covered roads is
expected. See Winter Tires on
page 10-42.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The
examples show a typical
passenger vehicle tire and a
compact spare tire sidewall.
Passenger (P-Metric) Tire Example
(1) Tire Size:The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,

Black plate (45,1)Buick Regal Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7576024) - 2015 - CRC - 9/15/14
Vehicle Care 10-45
(7) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet or
exceed all federal safety
guidelines.
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).

Black plate (55,1)Buick Regal Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7576024) - 2015 - CRC - 9/15/14
Vehicle Care 10-55
Replace the tire if:
.The indicators at three or
more places around the tire
can be seen.
.There is cord or fabric
showing through the tire's
rubber.
.The tread or sidewall is
cracked, cut, or snagged
deep enough to show cord or
fabric.
.The tire has a bump, bulge,
or split.
.The tire has a puncture, cut,
or other damage that cannot
be repaired well because of
the size or location of the
damage.
Tire Rotation
Tires should be rotated every
12 000 km (7,500 mi). See
Maintenance Schedule on
page 11-3.
Tires are rotated to achieve a
uniform wear for all tires. The
first rotation is the most
important.
Anytime unusual wear is
noticed, rotate the tires as soon
as possible, check for proper tire
inflation pressure, and check for
damaged tires or wheels. If the
unusual wear continues after the
rotation, check the wheel
alignment. SeeWhen It Is Time
for New Tires on page 10-56
and Wheel Replacement on
page 10-61.
Use this rotation pattern when
rotating the tires.
Do not include the compact
spare tire in the tire rotation.
Adjust the front and rear tires to
the recommended inflation
pressure on the Tire and
Loading Information label after
the tires have been rotated. See
Tire Pressure on page 10-48
and Vehicle Load Limits on
page 9-10.

Black plate (58,1)Buick Regal Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7576024) - 2015 - CRC - 9/15/14
10-58 Vehicle Care
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. Never exceed the winter
tires’maximum speed capability
when using winter tires with a
lower speed rating.
{Warning
Tires could explode during
improper service. Attempting
to mount or dismount a tire
could cause injury or death.
Only your dealer or authorized
tire service center should
mount or dismount the tires.
{Warning
Mixing tires of different sizes,
brands, or types may cause
loss of control of the vehicle,
resulting in a crash or other
vehicle damage. Use the
correct size, brand, and type
of tires on all wheels.
{Warning
Using bias-ply tires on the
vehicle may cause the wheel
rim flanges to develop cracks
after many miles of driving.
A tire and/or wheel could fail
suddenly and cause a crash.
Use only radial-ply tires with
the wheels on the vehicle.
If the vehicle tires must be
replaced with a tire that does not
have a TPC Spec number, make sure they are the same size,
load range, speed rating, and
construction (radial) as the
original tires.
Vehicles that have a tire
pressure monitoring system
could give an inaccurate
low-pressure warning if non-TPC
Spec rated tires are installed.
See
Tire Pressure Monitor
System on page 10-50.
The Tire and Loading
Information label indicates the
original equipment tires on the
vehicle. See Vehicle Load Limits
on page 9-10.
Different Size Tires and
Wheels
If wheels or tires are installed that
are a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover

Black plate (59,1)Buick Regal Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7576024) - 2015 - CRC - 9/15/14
Vehicle Care 10-59
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, electronic stability control,
or All-Wheel Drive, the performance
of these systems can also be
affected.
{Warning
If different sized wheels are used,
there may not be an acceptable
level of performance and safety if
tires not recommended for those
wheels are selected. This
increases the chance of a crash
and serious injury. Only use GM
specific wheel and tire systems
developed for the vehicle, and
have them properly installed by a
GM certified technician.
See Buying New Tires on
page 10-57 andAccessories and
Modifications on page 10-3.
Uniform Tire Quality
Grading
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires by
treadwear, traction, and
temperature performance. This
applies only to vehicles sold in
the United States. The grades
are molded on the sidewalls of
most passenger car tires. The
Uniform Tire Quality Grading
(UTQG) system does not apply
to deep tread, winter tires,
compact spare tires, tires with
nominal rim diameters of
10 to 12 inches (25 to 30 cm),
or to some limited-production
tires.
While the tires available on
General Motors passenger cars
and light trucks may vary with
respect to these grades, they must also conform to federal
safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width. For
example:
Treadwear 200 Traction AA
Temperature A
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.
Treadwear
The treadwear grade is a
comparative rating based on the
wear rate of the tire when tested
under controlled conditions on a
specified government test
course. For example, a tire
graded 150 would wear one and