2018 BUICK REGAL wheel size

Buick Regal Owner Manual (GMNA-Localizing-2nd Timed Print-U.S./Canada-
11486030) - 2018 - crc - 3/23/18
90 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, seat belts,
airbag sensing and diagnostic
module, steering wheel, instrumentpanel, inner door seals including the
speakers, any of the airbag
modules, ceiling or pillar garnish
trim, overhead console, 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
0 85.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels 0290 for additional
important information.
If you have to modify your vehicle
because you have a disability and
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 0348.
Airbag System Check
The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See
Airbag Readiness Light 0131.

Buick Regal Owner Manual (GMNA-Localizing-2nd Timed Print-U.S./Canada-
11486030) - 2018 - crc - 3/23/18
Driving and Operating 183
wheels stop spinning before shifting
gears. Release the accelerator
pedal while shifting, and press
lightly on the accelerator pedal
when the transmission is in gear.
Slowly spinning the wheels in the
forward and reverse directions
causes a rocking motion that could
free the vehicle. If that does not get
the vehicle out after a few tries, it
might need to be towed out. If the
vehicle does need to be towed out,
seeTowing the Vehicle 0318.
Vehicle Load Limits
It is very important to know how
much weight the vehicle can
carry. This weight is called the
vehicle capacity weight and
includes the weight of all
occupants, cargo, and all
nonfactory-installed options.
Two labels on the vehicle may
show how much weight it may
properly carry: the Tire and
Loading Information label and
the Certification label.
{Warning
Do not load the vehicle any
heavier than the Gross
Vehicle Weight Rating
(GVWR), or either the
maximum front or rear Gross
Axle Weight Rating (GAWR).
This can cause systems to
break and change the way the
vehicle handles. This could
cause loss of control and a
crash. Overloading can also
reduce stopping distance,
damage the tires, and shorten
the life of the vehicle. Tire and Loading Information
Label
Label Example
A vehicle-specific Tire and
Loading Information label is
attached to the vehicle's center
pillar (B-pillar). The Tire and
Loading Information label shows
the number of occupant seating
positions (1), and the maximum
vehicle capacity weight (2) in
kilograms and pounds.
The Tire and Loading
Information label also shows the
tire size of the original

Buick Regal Owner Manual (GMNA-Localizing-2nd Timed Print-U.S./Canada-
11486030) - 2018 - crc - 3/23/18
Driving and Operating 197
DSC allows you to shift an
automatic transmission similar to a
manual transmission. To use the
DSC feature:1. Move the shift lever to the left from D (Drive) into the side
gate marked with (+) and (−).
2. Move the shift lever forward to upshift or rearward to
downshift.
While using the DSC feature, the
vehicle will have firmer, quicker
shifting. You can use this for sport
driving or when climbing or descending hills, to stay in gear
longer, or to downshift for more
power or engine braking.
The transmission will only allow you
to shift into gears appropriate for the
vehicle speed and engine
revolutions per minute (rpm). The
transmission will not automatically
shift to the next lower gear if the
engine rpm is too high, nor to the
next higher gear when the maximum
engine rpm is reached.
While in the DSC mode, the
transmission will automatically
downshift when the vehicle comes
to a stop. This will allow for more
power during take-off.
When accelerating the vehicle from
a stop in snowy and icy conditions,
you may want to shift into second
gear. A higher gear allows the
vehicle to gain more traction on
slippery surfaces. Vehicles with a
turbocharged engine may also start
in third gear.
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. See
Compact
Spare Tire 0314.

Buick Regal Owner Manual (GMNA-Localizing-2nd Timed Print-U.S./Canada-
11486030) - 2018 - crc - 3/23/18
240 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . 241
California Proposition65 Warning . . . . . . . . . . . . . . . . . 241
California Perchlorate Materials Requirements . . . . . 242
Accessories and Modifications . . . . . . . . . . . . . . . . 242
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 242
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 243
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 244
Engine Oil . . . . . . . . . . . . . . . . . . . . 247
Engine Oil Life System . . . . . . . 249
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 250
Engine Air Cleaner/Filter . . . . . . 251
Cooling System . . . . . . . . . . . . . . 252
Engine Overheating . . . . . . . . . . 256
Washer Fluid . . . . . . . . . . . . . . . . . 257
Brakes . . . . . . . . . . . . . . . . . . . . . . . 258
Brake Fluid . . . . . . . . . . . . . . . . . . . 259
Battery - North America . . . . . . 260
All-Wheel Drive . . . . . . . . . . . . . . . 261 Starter Switch Check . . . . . . . . . 261
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 261
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 261
Wiper Blade Replacement . . . . 262
Windshield Replacement . . . . . 263
Gas Strut(s) . . . . . . . . . . . . . . . . . . 263
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 264
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 265
Halogen Bulbs . . . . . . . . . . . . . . . . 265
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 265
Headlamps . . . . . . . . . . . . . . . . . . . 265
Fog Lamps . . . . . . . . . . . . . . . . . . . 266
Front Turn Signal Lamps . . . . . 266
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 266
Electrical System
Electrical System Overload . . . 267
Fuses and Circuit Breakers . . . 268
Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . 268 Instrument Panel Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 272
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 274
All-Season Tires . . . . . . . . . . . . . . 275
Winter Tires . . . . . . . . . . . . . . . . . . 275
Low-Profile Tires . . . . . . . . . . . . . 275
Tire Sidewall Labeling . . . . . . . . 276
Tire Designations . . . . . . . . . . . . . 278
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 278
Tire Pressure . . . . . . . . . . . . . . . . . 281
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 282
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 283
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 284
Tire Inspection . . . . . . . . . . . . . . . . 287
Tire Rotation . . . . . . . . . . . . . . . . . 287
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 288
Buying New Tires . . . . . . . . . . . . . 289
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 290
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 291
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 292
Wheel Replacement . . . . . . . . . . 293

Buick Regal Owner Manual (GMNA-Localizing-2nd Timed Print-U.S./Canada-
11486030) - 2018 - crc - 3/23/18
Vehicle Care 275
All-Season Tires
This vehicle may come with
all-season tires. These tires are
designed to provide good overall
performance on most road surfaces
and weather conditions. Original
equipment tires designed to GM's
specific tire performance criteria
have a TPC specification code
molded onto the sidewall. Original
equipment all-season tires can be
identified by the last two characters
of this TPC code, which will
be“MS.”
Consider installing winter tires on
the vehicle if frequent driving on
snow or ice-covered roads is
expected. All-season tires provide
adequate performance for most
winter driving conditions, but they
may not offer the same level of
traction or performance as winter
tires on snow or ice-covered roads.
See Winter Tires 0275.
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 0289.
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.
Low-Profile Tires
If the vehicle has 245/45R18 or
245/40R19 size tires, they are
classified as low-profile tires.
Caution
Low-profile tires are more
susceptible to damage from road
hazards or curb impact than
standard profile tires. Tire and/or
wheel assembly damage can
occur when coming into contact
with road hazards like potholes,
or sharp edged objects, or when
sliding into a curb. The warranty
does not cover this type of
damage. Keep tires set to the
correct inflation pressure and (Continued)

Buick Regal Owner Manual (GMNA-Localizing-2nd Timed Print-U.S./Canada-
11486030) - 2018 - crc - 3/23/18
278 Vehicle Care
(6) Tire Size:A combination of
letters and numbers define a
tire's width, height, aspect ratio,
construction type, and service
description. The letter T as the
first character in the tire size
means the tire is for temporary
use only.
(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

Buick Regal Owner Manual (GMNA-Localizing-2nd Timed Print-U.S./Canada-
11486030) - 2018 - crc - 3/23/18
284 Vehicle Care
combined with the low tire pressure
telltale. When the system detects a
malfunction, the telltale will flash for
approximately one minute and then
remain continuously illuminated.
This sequence will continue upon
subsequent vehicle start-ups as
long as the malfunction exists.
When the malfunction indicator is
illuminated, the system may not be
able to detect or signal low tire
pressure as intended. TPMS
malfunctions may occur for a variety
of reasons, including the installation
of replacement or alternate tires or
wheels on the vehicle that prevent
the TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow the
TPMS to continue to function
properly.
SeeTire Pressure Monitor
Operation 0284.
See Radio Frequency Statement
0 356.Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure in
the tires and transmit the tire
pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.
If the warning light comes on, stop
as soon as possible and inflate the
tires to the recommended pressure shown on the Tire and Loading
Information label. See
Vehicle Load
Limits 0183.
A message to check the pressure in
a specific tire displays in the Driver
Information Center (DIC). The low
tire pressure warning light and the
DIC warning message come on at
each ignition cycle until the tires are
inflated to the correct inflation
pressure. Using the DIC, tire
pressure levels can be viewed. For
additional information and details
about the DIC operation and
displays see Driver Information
Center (DIC) 0141.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven. This
could be an early indicator that the
air pressure is getting low and
needs to be inflated to the proper
pressure.
A Tire and Loading Information
label, attached to your vehicle,
shows the size of the original
equipment tires and the correct
inflation pressure for the tires when

Buick Regal Owner Manual (GMNA-Localizing-2nd Timed Print-U.S./Canada-
11486030) - 2018 - crc - 3/23/18
Vehicle Care 287
8. Proceed to the passenger sidefront tire, and repeat the
procedure in Step 7.
9. Proceed to the passenger side rear tire, and repeat the
procedure in Step 7.
10. Proceed to the driver side rear tire, and repeat the procedure
in Step 7. The horn sounds two
times to indicate the sensor
identification code has been
matched to the driver side rear
tire, and the TPMS sensor
matching process is no longer
active. The TIRE LEARNING
ACTIVE message on the DIC
display screen goes off.
11. Turn the vehicle off.
12. Set all four tires to the recommended air pressure
level as indicated on the Tire
and Loading Information label.Tire Inspection
We recommend that the tires,
including the spare tire, if the
vehicle has one, be inspected
for signs of wear or damage at
least once a month.
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 0332.
Tires are rotated to achieve a
more 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.
See When It Is Time for New
Tires 0288 andWheel
Replacement 0293.