Ford E-250 (2006 year). Manual — part 29

12. Treadwear, Traction and Temperature 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 one-half (1

1

⁄

2

) times as well on the government

course as a tire graded 100.

• Traction: The traction grades, from highest to lowest are AA, A, B,

and C. The grades represent the tire’s ability to stop on wet pavement
as measured under controlled conditions on specified government test
surfaces of asphalt and concrete. A tire marked C may have poor
traction performance.

• Temperature: The temperature grades are A (the highest), B and C,

representing the tire’s resistance to the generation of heat and its
ability to dissipate heat when tested under controlled conditions on a
specified indoor laboratory test wheel.

13. Maximum Permissible Inflation Pressure: Indicates the tire
manufacturers’ maximum permissible pressure and/or the pressure at
which the maximum load can be carried by the tire. This pressure is
normally higher than the manufacturer’s recommended cold inflation
pressure which can be found on the Safety Compliance Certification
Label or Tire Label which is located on the B-Pillar or the edge of the
driver’s door. The cold inflation pressure should never be set lower than
the recommended pressure on the vehicle label.

The tire suppliers may have additional markings, notes or warnings such
as standard load, radial tubeless, etc.

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Additional information contained on the tire sidewall for “LT” type
tires

“LT” type tires have some additional
information beyond those of “P”
type tires; these differences are
described below:

1. LT: Indicates a tire, designated by
the Tire and Rim Association
(T&RA), that is intended for service
on light trucks.

2. Load Range/Load Inflation
Limits: Indicates the tire’s
load-carrying capabilities and its
inflation limits.

3. Maximum Load Dual lb. (kg)
at psi (kPa) cold: Indicates the
maximum load and tire pressure
when the tire is used as a dual; defined as four tires on the rear axle (a
total of six or more tires on the vehicle).

4. Maximum Load Single lb. (kg) at psi (kPa) cold: Indicates the
maximum load and tire pressure when the tire is used as a single;
defined as two tires (total) on the rear axle.

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Information on “T” type tires

“T” type tires have some additional
information beyond those of “P”
type tires; these differences are
described below:

T145/80D16 is an example of a tire
size.

Note: The temporary tire size for
your vehicle may be different from
this example.

1. T: Indicates a type of tire,
designated by the Tire and Rim
Association (T&RA), that is
intended for temporary service on
cars, SUVs, minivans and light
trucks.

2. 145: Indicates the nominal width
of the tire in millimeters from
sidewall edge to sidewall edge. In general, the larger the number, the
wider the tire.

3. 80: Indicates the aspect ratio which gives the tire’s ratio of height to
width. Numbers of 70 or lower indicate a short sidewall.

4. D: Indicates a “diagonal” type tire.
R: Indicates a “radial” type tire.

5. 16: Indicates the wheel or rim diameter in inches. If you change your
wheel size, you will have to purchase new tires to match the new wheel
diameter.

Location of the tire label

You will find a Tire Label containing tire inflation pressure by tire size
and other important information located on the B-Pillar or the edge of
the driver’s door. Refer to the payload description and graphic in the
Vehicle loading — with and without a trailer section.

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SNOW TIRES AND CHAINS

Snow tires must be the same size and grade as the tires you
currently have on your vehicle.

The tires on your vehicle have all weather treads to provide traction in
rain and snow. However, in some climates, you may need to use snow
tires and chains. If you need to use chains, it is recommended that steel
wheels (of the same size and specifications) be used, as chains may chip
aluminum wheels.

Follow these guidelines when using snow tires and chains:
• Use only SAE Class S chains.
• Install chains securely, verifying that the chains do not touch any

wiring, brake lines or fuel lines.

• Drive cautiously. If you hear the chains rub or bang against your

vehicle, stop and re-tighten the chains. If this does not work, remove
the chains to prevent damage to your vehicle.

• If possible, avoid fully loading your vehicle.
• Remove the tire chains when they are no longer needed. Do not use

tire chains on dry roads.

• The suspension insulation and bumpers will help prevent vehicle

damage. Do not remove these components from your vehicle when
using snow tires and chains.

VEHICLE LOADING – WITH AND WITHOUT A TRAILER

This section will guide you in the proper loading of your vehicle and/or
trailer, to keep your loaded vehicle weight within its design rating
capability, with or without a trailer. Properly loading your vehicle will
provide maximum return of vehicle design performance. Before loading
your vehicle, familiarize yourself with the following terms for determining
your vehicle’s weight ratings, with or without a trailer, from the vehicle’s
Tire Label or Safety Compliance Certification Label:

Base Curb Weight – is the weight of the vehicle including a full tank of
fuel and all standard equipment. It does not include passengers, cargo, or
optional equipment.

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