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Cracking
Any parting within the tread, sidewall, or inner liner of the tire extending to cord material.
Cold tire inflation pressure
The tire pressure recommended by the vehicle manufacturer for a tire of a specified size that has not
been driven for more than a couple of miles (kilometers) at low speeds in the 3 hour period before the
tire pressure is measured or adjusted.
Curb weight
The weight of a motor vehicle with standard equipment including the maximum capacity of fuel, oil,
and coolant, air conditioner, and additional weight of optional equipment.
Extra load tire
A tire designed to operate at higher loads and at higher inflation pressures than the corresponding
standard tire.
Gross Axle Weight Rating (GAWR)
The load-carrying capacity of a single axle system, measured where the tire contacts the ground.
Gross Vehicle Weight Rating (GVWR)
The maximum loaded weight of the vehicle.
Groove
The space between 2 adjacent tread ribs.
Load rating (code)
The maximum load that a tire is rated to carry for a given inflation pressure. You may not find this
information on all tires because it is not required by law.
Maximum load rating
The load rating for a tire at the maximum permissible inflation pressure for that tire.
Maximum loaded vehicle weight
The total of:
x Curb weight.
x Accessory weight.
x Vehicle capacity weight.
x Production options weight.
Maximum (permissible) inflation pressure
The maximum cold inflation pressure to which a tire may be inflated. Also called “maximum inflation
pressure.”
Normal occupant weight
Means lbs (68 kilograms) times the number of occupants seated in the vehicle up to the total seating
capacity of your vehicle.
Occupant distribution
The placement of passengers in a vehicle.
Outer diameter
The diameter of a new, properly inflated tire.
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Overall width
Total width measured at the exterior sidewalls of an inflated tire, including the additional width of
labeling, decorations, or protective bands or ribs.
Passenger car tire
A tire intended for use on passenger cars, multipurpose passenger vehicles, and trucks, that have a
gross vehicle weight rating (GVWR) of 10, pounds or less.
Ply
A layer of rubber-coated parallel cords. A parting of rubber compound between adjacent plies.
Ply separation
A parting of rubber compound between adjacent plies.
Pneumatic tire
A mechanical device made of rubber, chemicals, fabric, and steel or other materials, that, when
mounted on an automotive wheel, provides the traction and contains the gas or fluid that sustains the
load.
Production options weight
The combined weight of installed regular production options weighing over 5 lbs (2.3 kg) more then the
standard items they replace, and not previously considered as curb weight or accessory weight. These
include, for example, heavy-duty brakes, ride levelers, heavy-duty battery, and special trim.
Radial ply tires
A pneumatic tire in which the ply cords that extend to the beads are laid at substantially 90 degrees to
the centerline of the tread.
Recommended inflation pressure
The tire pressure recommended by the vehicle manufacturer for a tire of a specified size that has not
been driven for more than a couple of miles (kilometers) at low speeds in the 3 hour period before the
tire pressure is measured or adjusted.
Reinforced tire
A tire designed to operate at higher loads and at higher inflation pressures than the corresponding
standard tire.
Rim
The outer edge of a wheel upon which the tire beads are seated.
Rim diameter
The nominal diameter of the wheel's tire bead seating surface. If you change your wheel size, to
wheels of a different diameter, you will have to purchase new tires to match the new wheels.
Rim size
Designation means rim diameter and width.
Rim type designation
The industry or manufacturer's designation for a rim by style or code.
Rim width
The nominal distance between wheel rim flanges.
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Section width
The linear distance between the exteriors of the sidewalls of an inflated tire, excluding elevations due
to labeling decoration, or protective bands.
Sidewall
The portion of a tire between the bead and the tread.
Sidewall separation
The parting of the rubber compound from the cord material in the sidewall.
Speed rating (letter code)
A standardized letter code indicating the maximum speed at which a tire is designed to be driven for
extended periods of time. The ratings range from 93 mph or km/h (“P”) to mph or ( km/h) “Y”.
The speed rating letter code, where applicable, is molded on the tire sidewall 297, Speed rating
code letter. You may not find this information on all tires because it is not required by law.
Tire Pressure Monitoring System
A system that detects when at least one of a vehicle's tires is underinflated and illuminates a low tire-
pressure warning light.
Tread
The portion of a tire that normally touches the road.
Tread rib
A tread section running circumferentially around a tire.
Tread separation
Tire failure caused by the tread pulling away from the tire carcass.
Tread wear indicators (TWI)
Raised areas within the main tread grooves that show, visually, when tires are worn and near the end
of their useful life, Tread depth and tread wear indicators.
Uniform Tire Quality Grading (UTQG)
A tire information system developed by the U.S. National Highway Traffic Safety Administration
(NHTSA) that is designed to help buyers compare tires. UTQG is not a safety rating, nor is it a
guarantee that a tire will last for a certain number of miles or perform a certain way. It gives tire buyers
more information to compare with factors such as price, brand loyalty and dealer recommendations.
Under UTQG, tires are graded by the tire manufacturers in 3 areas: tread wear, traction and
temperature resistance. UTQG information is molded into the tire sidewalls.
U.S. DOT Tire Identification Number (TIN)
A tire's serial number. It begins with the letters “DOT” (“Department of Transportation”) and indicates
that the tire meets all federal standards. The next 2 numbers or letters indicate the plant where the tire
was manufactured. The last 4 numbers represent the week and year of manufacture.
For example, the numbers 1 mean that the tire was produced in the 18th week of 1. Any other
numbers are marketing codes used by the tire manufacturer. This information is used to help identify
affected consumers if a tire defect requires a recall.
Vehicle capacity weight
The total rated cargo, luggage and passenger load. Passenger load is lbs (68 kilograms) times the
vehicle's total seating capacity (as listed on the label inside the driver door).
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These electronic control modules also record data during normal vehicle operation for diagnostic and
repair purposes. Their recording capability is limited to data (no sound is recorded). Only a small
amount of data is actually recorded over a very limited period of time, or stored when a system fault is
detected by a control module. Some of the data stored may relate to vehicle speed, direction, or
braking, as well as restraint system use and performance in the event of a crash. Stored data can only
be read and downloaded with special equipment.
Using a cellular phone in a motor vehicle when it is not connected to
the vehicle telephone antenna - some important things to know
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The relative performance of tires depends upon the actual conditions of their use, however, and may
depart significantly from the norm due to variations in driving habits, service practices and differences
in road characteristics and climate.
Traction
The traction grades from highest to lowest, are AA, A, B and C. Those 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.
Sustained high temperature can cause the material of the tire to degenerate and reduce tire life, and
excessive temperature can lead to sudden tire failure.
The grade C corresponds to a level of performance which all passenger car tires must meet under the
Federal Motor Vehicle Safety Standard No. . Grades B and A represent higher levels of performance
on the laboratory test wheel than the minimum required by law ⇒ .
WARNING
The traction grade assigned to this tire is based on straight-ahead braking traction tests, and
does not include acceleration, cornering, hydroplaning or peak traction characteristics.
WARNING
The temperature grade for this tire is established for a tire that is properly inflated and not
overloaded. Excessive speed, underinflation or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
Volkswagen service information
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Description Possible causes among
others Possible remedy
Tire pressure too low. Adjust tire pressure
Driving in the mountains. No direct corrective action possible.
Towing a trailer or driving with
a roof rack.
– Check use.
– Remove if not in use.
Driving with heavy payload. No direct corrective action possible.
Driving at high engine speed. Select a higher gear.