GMC Terrain: Wheels and Tires / Tire Designations
Tire Size
The following is an example of a
typical passenger vehicle
tire size.

- 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.
- Tire Width : The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
- 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.
- 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.
- Rim Diameter : Diameter of
the wheel in inches.
- 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.
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
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,
and service description...
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)...
Other information:
Metric Uplevel
English Uplevel
When the ignition is on, the fuel
gauge indicates about how much
fuel is left in the tank.
An arrow on the fuel gauge
indicates the side of the vehicle the
fuel door is on.
When the indicator nears empty, the
low fuel light comes on...
Info Page Options
The info pages on the DIC can be
turned on or off through the
Options menu.
Press to access the cluster
applications.
Press or
to scroll to the
Options application.
Press to enter the
Options menu.
Scroll to Info Pages and
press ...