Chevrolet BOLT EV Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
12163003) - 2019 - crc - 5/18/18
Vehicle Care 283
Aspect Ratio:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords that is located between
the plies and the tread. Cords
may be made from steel or other
reinforcing materials.
Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Bias Ply Tire
:A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in kPa (kilopascal)
or psi (pounds per square inch)
before a tire has built up heat
from driving. See Tire Pressure
0 285. Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the
maximum capacity of fuel, oil,
and coolant, but without
passengers and cargo.
DOT Markings
:A code molded
into the sidewall of a tire
signifying that the tire is in
compliance with the U.S.
Department of Transportation
(DOT) Motor Vehicle Safety
Standards. The DOT code
includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and
date of production.
GAWR FRT
:Gross Axle Weight
Rating for the front axle. See
Vehicle Load Limits 0201.
GAWR RR
:Gross Axle Weight
Rating for the rear axle. See
Vehicle Load Limits 0201. GVWR
:Gross Vehicle Weight
Rating. See Vehicle Load Limits
0 201.
Intended Outboard Sidewall
:
The side of an asymmetrical tire,
that must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The metric
unit for air pressure.
Light Truck (LT-Metric) Tire
:A
tire used on light duty trucks and
some multipurpose passenger
vehicles.
Load Index
:An assigned
number ranging from 1 to 279
that corresponds to the load
carrying capacity of a tire.
Maximum Inflation Pressure
:
The maximum air pressure to
which a cold tire can be inflated.
The maximum air pressure is
molded onto the sidewall.
Chevrolet BOLT EV Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
12163003) - 2019 - crc - 5/18/18
286 Vehicle Care
When to Check
Check the tires once a month
or more.
How to Check
Use a good quality pocket-type
gauge to check the tire
pressure. Proper tire inflation
cannot be determined by looking
at the tire. Check the tire
inflation pressure when the tires
are cold, meaning the vehicle
has not been driven for at least
three hours or no more than
1.6 km (1 mi).
Remove the valve cap from the
tire valve stem. Press the tire
gauge firmly onto the valve to
get the pressure measurement.
If the cold tire inflation pressure
matches the recommended
pressure on the Tire and
Loading Information label, no
further adjustment is necessary.If the inflation pressure is low,
add air until the recommended
pressure is reached. If the
inflation pressure in high, press
on the metal stem in the center
of the tire valve to release air.
Re-check the tire pressure with
the tire gauge.
Put the valve caps back on the
valve stems to keep out dirt and
moisture and prevent leaks. Use
only valve caps designed for the
vehicle by GM. TPMS sensors
could be damaged and would
not be covered by the vehicle
warranty.
Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your tires and
transmit tire pressure readings to a
receiver located in the vehicle. Each tire, including the spare (if
provided), should be checked
monthly when cold and inflated to
the inflation pressure recommended
by the vehicle manufacturer on the
vehicle placard or tire inflation
pressure label. (If your vehicle has
tires of a different size than the size
indicated on the vehicle placard or
tire inflation pressure label, you
should determine the proper tire
inflation pressure for those tires.)
As an added safety feature, your
vehicle has been equipped with a
tire pressure monitoring system
(TPMS) that illuminates a low tire
pressure telltale when one or more
of your tires is significantly
under-inflated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires as
soon as possible, and inflate them
to the proper pressure. Driving on a
significantly under-inflated tire
causes the tire to overheat and can
lead to tire failure. Under-inflation
also reduces fuel efficiency and tire
