2018 Ram ProMaster User Guide

• High flotation tire sizing is based on U.S.design standards and it begins with the tire
diameter molded into the sidewall. Ex-
ample: 31x10.5 R15 LT.
Tire Sizing Chart
EXAMPLE:
Example Size Designation: P215/65R15XL 95H, 215/65R15 96H, LT235/85R16C, T145/80D18 103M, 31x10.5 R15 LT
P = Passenger car tire size based on U.S. design standards, or
"....blank...." = Passenger car tire based on European design standards, or
LT = Light truck tire based on U.S. design standards, or
TorS= Temporary spare tire or
31 = Overall diameter in inches (in)
215, 235, 145 = Section width in millimeters (mm)
65, 85, 80 = Aspect ratio in percent (%)
• Ratio of section height to section width of tire, or
10.5 = Section width in inches (in)
R = Construction code
• "R" means radial construction, or
• "D" means diagonal or bias construction
15, 16, 18 = Rim diameter in inches (in)
135

EXAMPLE:
Service Description:
95 = Load Index
• A numerical code associated with the maximum load a tire can carry
H = Speed Symbol
• A symbol indicating the range of speeds at which a tire can carry a load corresponding to its load index under certain operating conditions
• The maximum speed corresponding to the speed symbol should only be achieved under specified operating conditions (i.e., tire pressure, vehicle
loading, road conditions, and posted speed limits)
Load Identification:
Absence of the following load identification symbols on the sidewall of the tire indicates a Standard Load (SL) tire:
• XL= Extra load (or reinforced) tire, or
• LL= Light load tire or
• C, D, E, F, G = Load range associated with the maximum load a tire can carry at a specified pressure
Maximum Load – Maximum load indicates the maximum load this tire is designed to carry
Maximum Pressure – Maximum pressure indicates the maximum permissible cold tire inflation pressure for this tire
SERVICING AND MAINTENANCE
136

Tire Identification Number (TIN)
The TIN may be found on one or both sides of
the tire; however, the date code may only be
on one side. Tires with white sidewalls will
have the full TIN, including the date code,located on the white sidewall side of the tire.
Look for the TIN on the outboard side of black
sidewall tires as mounted on the vehicle. If
the TIN is not found on the outboard side,
then you will find it on the inboard side of the
tire.
EXAMPLE:
DOT MA L9 ABCD 0301
DOT = Department of Transportation
• This symbol certifies that the tire is in compliance with the U.S. Department of Transportation tire safety standards and is approved for highway
use
MA = Code representing the tire manufacturing location (two digits)
L9 = Code representing the tire size (two digits)
ABCD = Code used by the tire manufacturer (one to four digits)
03 = Number representing the week in which the tire was manufactured (two digits)
• 03 means the 3rd week
01 = Number representing the year in which the tire was manufactured (two digits)
• 01 means the year 2001
• Prior to July 2000, tire manufacturers were only required to have one number to represent the year in which the tire was manufactured. Example:
031 could represent the 3rd week of 1981 or 1991
137

Tire Terminology And Definitions
TermDefinition
B-Pillar The vehicle B-Pillar is the structural member of the body located behind the front
door.
Cold Tire Inflation Pressure Cold tire inflation pressure is defined as the tire pressure after the vehicle has not
been driven for at least three hours, or driven less than 1 mile (1.6 km) after sitting
for a minimum of three hours. Inflation pressure is measured in units of PSI (pounds
per square inch) or kPa (kilopascals).
Maximum Inflation Pressure The maximum inflation pressure is the maximum permissible cold tire inflation pres-
sure for this tire. The maximum inflation pressure is molded into the sidewall.
Recommended Cold Tire Inflation Pressure Vehicle manufacturer's recommended cold tire inflation pressure as shown on the tire
placard.
Tire Placard A label permanently attached to the vehicle describing the vehicle’s loading capacity,
the original equipment tire sizes and the recommended cold tire inflation pressures.
SERVICING AND MAINTENANCE
138

Tire Loading And Tire Pressure
NOTE:
The proper cold tire inflation pressure is
listed on the driver’s side B-Pillar or the rear
edge of the driver's side door.
Check the inflation pressure of each tire,
including the spare tire (if equipped), at least
monthly and inflate to the recommended
pressure for your vehicle.Tire And Loading Information PlacardThis placard tells you important information
about the:
1. Number of people that can be carried in
the vehicle.
2. Total weight your vehicle can carry.
3. Tire size designed for your vehicle.
4. Cold tire inflation pressures for the front, rear, and spare tires.
Loading
The vehicle maximum load on the tire must
not exceed the load carrying capacity of the
tire on your vehicle. You will not exceed the
tire's load carrying capacity if you adhere to
the loading conditions, tire size, and cold tire
inflation pressures specified on the Tire and
Loading Information placard in “Vehicle
Loading” in the “Starting And Operating”
section of this manual.
NOTE:
Under a maximum loaded vehicle condition,
gross axle weight ratings (GAWRs) for the
front and rear axles must not be exceeded.
Example Tire Placard Location (Door)
Example Tire Placard Location (B-Pillar)
Tire And Loading Information Placard
139

To determine the maximum loading condi-
tions of your vehicle, locate the statement
“The combined weight of occupants and
cargo should never exceed XXX kg or XXX lbs”
on the Tire and Loading Information placard.
The combined weight of occupants, cargo/
luggage and trailer tongue weight (if appli-
cable) should never exceed the weight refer-
enced here.
Steps For Determining Correct Load
Limit—
(1) Locate the statement “The com-
bined weight of occupants and cargo
should never exceed XXX kg or
XXX lbs.” on your vehicle's placard.
(2) Determine the combined weight of
the driver and passengers that will be
riding in your vehicle.
(3) Subtract the combined weight of
the driver and passengers from XXX kg
or XXX lbs.(4) The resulting figure equals the
available amount of cargo and luggage
load capacity. For example, if “XXX”
amount equals 1400 lbs. and there
will be five 150 lb passengers in your
vehicle, the amount of available cargo
and luggage load capacity is 650 lbs.
(1400-750 (5x150) = 650 lbs.)
(5) Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely
exceed the available cargo and lug-
gage load capacity calculated in Step
4.
(6) If your vehicle will be towing a
trailer, load from your trailer will be
transferred to your vehicle. Consult
this manual to determine how this
reduces the available cargo and lug-
gage load capacity of your vehicle.
Metric Example For Load Limit
For example, if “XXX” amount equals 635 kg
and there will be five 68 kg passengers in
your vehicle, the amount of available cargo
and luggage load capacity is 295 kg (635-
340 (5x68) = 295 kg) as shown in step 4.
NOTE:
• If your vehicle will be towing a trailer, load
from your trailer will be transferred to your
vehicle. The following table shows ex-
amples on how to calculate total load,
cargo/luggage, and towing capacities of
your vehicle with varying seating configura-
tions and number and size of occupants.
This table is for illustration purposes only
and may not be accurate for the seating and
load carry capacity of your vehicle.
SERVICING AND MAINTENANCE
140

• For the following example, the combinedweight of occupants and cargo should never
exceed 865 lbs (392 kg).
141

WARNING!
Overloading of your tires is dangerous.
Overloading can cause tire failure, affect
vehicle handling, and increase your stop-
ping distance. Use tires of the recom-
mended load capacity for your vehicle.
Never overload them.
Tires — General Information
Tire Pressure
Proper tire inflation pressure is essential to
the safe and satisfactory operation of your
vehicle. Four primary areas are affected by
improper tire pressure:
• Safety and Vehicle Stability
• Economy
• Tread Wear
• Ride ComfortSafety
WARNING!
• Improperly inflated tires are dangerous
and can cause collisions.
• Underinflation increases tire flexing and
can result in overheating and tire failure.
• Overinflation reduces a tire's ability to cushion shock. Objects on the road and
chuckholes can cause damage that re-
sult in tire failure.
• Overinflated or underinflated tires can
affect vehicle handling and can fail sud-
denly, resulting in loss of vehicle con-
trol.
• Unequal tire pressures can cause steer-
ing problems. You could lose control of
your vehicle.
• Unequal tire pressures from one side of
the vehicle to the other can cause the
vehicle to drift to the right or left.
• Always drive with each tire inflated to
the recommended cold tire inflation
pressure. Both under-inflation and over-inflation affect
the stability of the vehicle and can produce a
feeling of sluggish response or over respon-
siveness in the steering.
NOTE:
• Unequal tire pressures from side to side
may cause erratic and unpredictable steer-
ing response.
• Unequal tire pressure from side to side may cause the vehicle to drift left or right.
Fuel Economy
Underinflated tires will increase tire rolling
resistance resulting in higher fuel consump-
tion.
Tread Wear
Improper cold tire inflation pressures can
cause abnormal wear patterns and reduced
tread life, resulting in the need for earlier tire
replacement.
Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a comfort-
able ride. Over-inflation produces a jarring
and uncomfortable ride.
SERVICING AND MAINTENANCE
142