2008 FORD F SERIES MOTORHOME AND COMMERCIAL CHASSIS wheel size

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
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.
Vehicle Curb Weight– is the weight of your new vehicle when you
picked it up from your authorized dealer plus any aftermarket
equipment.
2008 Motorhome(mot)
Supplement
USA(fus)
Tires, Wheels and Loading
39

replace it as soon as possible with a road tire/wheel that is the same size
and type as the road tires and wheels that were originally provided by
Ford. If the dissimilar spare tire or wheel is damaged, it should be
replaced rather than repaired.
A dissimilar spare tire/wheel is defined as a spare tire and/or wheel that
is different in brand, size or appearance from the road tires and wheels
and can be one of three types:
1.T-type mini-spare:This spare tire begins with the letter “T” for tire
size and may have “Temporary Use Only” molded in the sidewall
2.Full-size dissimilar spare with label on wheel:This spare tire has
a label on the wheel that states: “THIS TIRE AND WHEEL FOR
TEMPORARY USE ONLY”
When driving with one of the dissimilar spare tires listed above,do not:
•Exceed 50 mph (80 km/h)
•Load the vehicle beyond maximum vehicle load rating listed on the
Safety Compliance Label
•Tow a trailer
•Use snow chains on the end of the vehicle with the dissimilar spare
tire
•Use more than one dissimilar spare tire at a time
•Use commercial car washing equipment
•Try to repair the dissimilar spare tire
Use of one of the dissimilar spare tires listed above at any one wheel
location can lead to impairment of the following:
•Handling, stability and braking performance
•Comfort and noise
•Ground clearance and parking at curbs
•Winter weather driving capability
•Wet weather driving capability
3.Full-size dissimilar spare without label on wheel
When driving with the full-size dissimilar spare tire/wheel,do not:
•Exceed 70 mph (113 km/h)
•Use more than one dissimilar spare tire/wheel at a time
•Use commercial car washing equipment
2008 Motorhome(mot)
Supplement
USA(fus)
Roadside Emergencies
70

•Use snow chains on the end of the vehicle with the dissimilar spare
tire/wheel
The usage of a full-size dissimilar spare tire/wheel can lead to
impairment of the following:
•Handling, stability and braking performance
•Comfort and noise
•Ground clearance and parking at curbs
•Winter weather driving capability
•Wet weather driving capability
•All-Wheel driving capability (if applicable)
•Load leveling adjustment (if applicable)
When driving with the full-size dissimilar spare tire/wheel additional
caution should be given to:
•Towing a trailer
•Driving vehicles equipped with a camper body
•Driving vehicles with a load on the cargo rack
Drive cautiously when using a full-size dissimilar spare tire/wheel and
seek service as soon as possible.
Stopping and securing the vehicle
1. Park on a level surface.
2. Activate the warning flashers.
3. Place the gearshift in P (Park).
2008 Motorhome(mot)
Supplement
USA(fus)
Roadside Emergencies
71

WHEEL LUG NUT TORQUE SPECIFICATIONS
On vehicles equipped with dual rear wheels, retighten the wheel lug nuts
to the specified torque at 100 miles (160 km), and again at 500 miles
(800 km) of new vehicle operation and after any wheel disturbance (tire
rotation, changing a flat tire, wheel removal, etc.).
Bolt size Wheel lug nut torque*
lb.ft. N•m
19.5 in. wheels: M14 x
1.5150 200
22.5 in. wheels: M22 x
1.5450 610
* Torque specifications are for nut and bolt threads free of dirt and
rust. Use only Ford recommended replacement fasteners.
On all two-piece flat wheel nuts,
apply one drop of motor oil between
the flat washer and the nut. Do not
apply motor oil to the wheel nut
threads or the wheel stud threads.
WARNING:When a wheel is installed, always remove any
corrosion, dirt or foreign materials present on the mounting
surfaces of the wheel or the surface of the wheel hub, brake drum or
brake disc that contacts the wheel. Ensure that any fasteners that
attach the rotor to the hub are secured so they do not interfere with
the mounting surfaces of the wheel. Installing wheels without correct
metal-to-metal contact at the wheel mounting surfaces can cause the
wheel nuts to loosen and the wheel to come off while the vehicle is in
motion, resulting in loss of control.
JUMP STARTING
WARNING:The gases around the battery can explode if
exposed to flames, sparks, or lit cigarettes. An explosion could
result in injury or vehicle damage.
2008 Motorhome(mot)
Supplement
USA(fus)
Roadside Emergencies
75

•Resting your foot on the brake pedal while driving may reduce fuel
economy.
•Combine errands and minimize stop-and-go driving.
Maintenance
•Keep tires properly inflated and use only recommended size.
•Operating a vehicle with the wheels out of alignment will reduce fuel
economy.
•Use recommended engine oil. Refer toMaintenance product
specifications and capacitiesin this chapter.
•Perform all regularly scheduled maintenance items. Follow the
recommended maintenance schedule and owner maintenance checks
found inscheduled maintenance information.
Conditions
•Heavily loading a vehicle or towing a trailer may reduce fuel economy
at any speed.
•Carrying unnecessary weight may reduce fuel economy (approximately
1 mpg [0.4 km/L] is lost for every 400 lb [180 kg] of weight carried).
•Adding certain accessories to your vehicle (for example bug
deflectors, rollbars/light bars, running boards, ski/luggage racks) may
reduce fuel economy.
•Using fuel blended with alcohol may lower fuel economy.
•Fuel economy may decrease with lower temperatures during the first
8–10 miles (12–16 km) of driving.
•Driving on flat terrain offers improved fuel economy as compared to
driving on hilly terrain.
•Transmissions give their best fuel economy when operated in the top
cruise gear and with steady pressure on the gas pedal.
•Close windows for high speed driving.
EPA fuel economy estimates
Every new vehicle should have a window sticker containing EPA fuel
economy estimates. Contact your authorized dealer if the window sticker
is not supplied with your vehicle. The EPA fuel economy estimates
should be your guide for the fuel economy comparisons with other
vehicles. Your fuel economy may vary depending upon the method of
operation and conditions.
2008 Motorhome(mot)
Supplement
USA(fus)
Maintenance and Specifications
108