4.R:Indicates a “radial” type tire.
5.15: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.
6.95:Indicates the tire’s load index. It is an index that relates to how
much weight a tire can carry. You may find this information in your
Owner’s Guide.If not, contact a local tire dealer.
Note:You may not find this information on all tires because it is not
required by federal law.
7.H:Indicates the tire’s speed rating. The speed rating denotes the
speed at which a tire is designed to be driven for extended periods of
time under a standard condition of load and inflation pressure. The tires
on your vehicle may operate at different conditions for load and inflation
pressure. These speed ratings may need to be adjusted for the difference
in conditions. The ratings range from 81 mph (130 km/h) to 186 mph
(299 km/h). These ratings are listed in the following chart.
Note:You may not find this information on all tires because it is not
required by federal law.
Letter rating Speed rating - mph (km/h)
M 81 mph (130 km/h)
N 87 mph (140 km/h)
Q 99 mph (159 km/h)
R 106 mph (171 km/h)
S 112 mph (180 km/h)
T 118 mph (190 km/h)
U 124 mph (200 km/h)
H 130 mph (210 km/h)
V 149 mph (240 km/h)
W 168 mph (270 km/h)
Y 186 mph (299 km/h)
Note:For tires with a maximum speed capability over 149 mph (240
km/h), tire manufacturers sometimes use the letters ZR. For those with
a maximum speed capability over 186 mph (299 km/h), tire
manufacturers always use the letters ZR.
2007 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
170
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.
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.
2007 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
172
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 trailersection.
2007 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
173
any tire is under-inflated, carefully drive the vehicle to the nearest
location where air can be added to the tires. Inflate all the tires to the
recommended inflation pressure.
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 cable type chains or chains offered by Ford as an accessory
or equivalent. Other conventional link type chains may contact and
cause damage to the vehicle’s wheel house and/or body.
•Do not install chains on the front wheels. Chains on the front wheels
may interfere with suspension components.
•Chains are not recommended for use on the P275/55R20 tire.
•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.
•Do not exceed 30 mph (48 km/h) with tire chains on your vehicle.
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
2007 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
178
•A final example for your vehicle with 1400 lb. (635 kg) of cargo and
luggage capacity. You and one of your friends decide to pick up
cement from the local home improvement store to finish that patio
you have been planning for the past 2 years. Measuring the inside of
the vehicle with the rear seat folded down, you have room for 12-100
lb. (45 kg) bags of cement. Do you have enough load capacity to
transport the cement to your home? If you and your friend each weigh
220 lb. (99 kg), the calculation would be: 1400 – (2 x 220) –
(12 x 100) = 1400 – 440 – 1200 = – 240 lb. No, you do not have
enough cargo capacity to carry that much weight. In metric units, the
calculation would be: 635 kg — (2 x 99 kg) — (12 x 45 kg) = 635 —
198 — 540 = —103 kg. You will need to reduce the load weight by at
least 240 lb. (104 kg). If you remove 3-100 lb. (45 kg) cement bags,
then the load calculation would be:
1400 – (2 x 220) – (9 x 100) = 1400 – 440 – 900 = 60 lb. Now you
have the load capacity to transport the cement and your friend home.
In metric units, the calculation would be: 635 kg — (2 x 99 kg) —
(9 x 45 kg) = 635 — 198 — 405 = 32 kg.
The above calculations also assume that the loads are positioned in your
vehicle in a manner that does not overload the Front or the Rear Gross
Axle Weight Rating specified for your vehicle on the Safety Compliance
Certification Label found on the edge of the driver’s door.
Special loading instructions for owners of pickup trucks and
utility-type vehicles
For important information regarding safe operation of this type
of vehicle, see thePreparing to drive your vehiclesection in
theDrivingchapter of this owner guide.
Loaded vehicles, with a higher center of gravity, may handle
differently than unloaded vehicles. Extra precautions, such as
slower speeds and increased stopping distance, should be taken when
driving a heavily loaded vehicle.
Your vehicle has the capability to haul more cargo and people than most
passenger cars. Depending upon the type and placement of the load,
hauling cargo and people may raise the center of gravity of the vehicle.
TRAILER TOWING
Trailer towing puts additional loads on your vehicle’s engine, transmission,
axle, brakes, tires, and suspension. For your safety and to maximize vehicle
performance, be sure to use the proper equipment while towing.
2007 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
184
Safety chains
Always connect the trailer’s safety chains to the frame or hook retainers
of the vehicle hitch. To connect the trailer’s safety chains, cross the
chains under the trailer tongue and allow slack for turning corners.
If you use a rental trailer, follow the instructions that the rental agency
gives to you.
Do not attach safety chains to the bumper.
Trailer brakes
Electric brakes and manual, automatic or surge-type trailer brakes are
safe if installed properly and adjusted to the manufacturer’s
specifications. The trailer brakes must meet local and Federal
regulations.
Do not connect a trailer’s hydraulic brake system directly to your
vehicle’s brake system. Your vehicle may not have enough
braking power and your chances of having a collision greatly increase.
The braking system of the tow vehicle is rated for operation at the
GVWR not GCWR.
Trailer lamps
Trailer lamps are required on most towed vehicles. Make sure all running
lights, brake lights, turn signals and hazard lights are working. See your
authorized dealer or trailer rental agency for proper instructions and
equipment for hooking up trailer lamps.
Driving while you tow
When towing a trailer:
•Keep your speed no faster than 70 mph (112 km/h) during the first
500 miles (800 km) of towing a trailer, and don’t make full throttle
starts.
•Turn off the speed control. The speed control may shut off
automatically when you are towing on long, steep grades.
•Consult your local motor vehicle speed regulations for towing a trailer.
•To eliminate excessive shifting, use a lower gear. This will also assist
in transmission cooling. (For additional information, refer to the
Understanding the positions of the 6–speed automatic
transmissionsection in this chapter.
2007 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
189
PREPARING TO DRIVE
Utility vehicles have a significantly higher rollover rate than
other types of vehicles.
In a rollover crash, an unbelted person is significantly more likely
to die than a person wearing a seat belt.
Your vehicle has special design and equipment features to make it
capable of performing in a wide variety of circumstances. These special
design features, such as larger tires and increased ground clearance, give
the vehicle a higher center of gravity than a passenger car.
Vehicles with a higher center of gravity such as utility and
four-wheel drive vehicles handle differently than vehicles with a
lower center of gravity. Utility and four-wheel drive vehicles arenot
designed for cornering at speeds as high as passenger cars any more
than low-slung sports cars are designed to perform satisfactorily under
off-road conditions. Avoid sharp turns, excessive speed and abrupt
maneuvers in these vehicles. Failure to drive cautiously could result in
an increased risk of loss of vehicle control, vehicle rollover, personal
injury and death.
Loaded vehicles, with a higher center of gravity, may handle
differently than unloaded vehicles. Extra precautions, such as
slower speeds and increased stopping distance, should be taken when
driving a heavily loaded vehicle.
Your vehicle has the capability to haul more cargo and people than most
passenger cars. Depending upon the type and placement of the load,
hauling people and cargo may raise the center of gravity of the vehicle.
Use extra caution while becoming familiar with your vehicle. Know the
capabilities and limitations of both you as a driver and your vehicle.
AUTOMATIC TRANSMISSION OPERATION
Brake-shift interlock – floor-shift transmission
This vehicle is equipped with a brake-shift interlock feature that prevents
the gearshift lever from being moved from P (Park) when the ignition is
in the ON position unless the brake pedal is depressed.
2007 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
205
CONTROL TRAC FOUR-WHEEL DRIVE (4X4) OPERATION
(IF EQUIPPED)
For important information regarding safe operation of this type
of vehicle, seePreparing to drive your vehiclein this chapter.
Do not use 4X4 mode on dry, hard surfaced roads. Doing so will produce
excessive noise, increase tire wear and may damage drive components.
4X4 mode is only intended for consistently slippery or loose surfaces.
Use of 4X4 mode on these surfaces may produce some noise (such as
occasional clunks) but will not damage drive components.
Your 4x4 features the heavy-duty Control Trac system which includes a
computer-operated transfer case. This unique system is interactive with
the road, continually monitoring and adjusting torque delivery to the
front and rear wheels to optimize vehicle control.
System indicator messages
The Control Trac system indicator messages display in the reconfigurable
telltale (RTT) location in the message center only under the following
conditions. If these messages display when driving in 4X2, contact your
authorized dealer as soon as possible. Refer toWarning lights and
chimesin theInstrument Clusterchapter.
•4X4 AUTO– displays when 4X4 AUTO is selected.
•4X4– displays when 4X4 is selected.
Positions of the Control Trac system
The Control Trac system functions
in three modes:
•4X2 (2WD)delivers power to
the rear wheels only. This is
appropriate for normal on-road
driving on dry pavement.
•4X4 AUTOprovides electronic
control four-wheel drive with power delivered to all four wheels, as
required, for increased traction. The RTT location in the message
center will display “4X4 AUTO” when this position is selected. This is
appropriate for all on-road driving conditions, such as dry road
surfaces, wet pavement, snow or gravel.
4X24X4
AUTO4X4
2007 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
212