A special drive technology which is capable of powering all car wheels at the same time. There are different variations of this system. Some of them can be activated at any given moment, while others are installed permanently. The 4-wheel drive powers the tires in relation to the road’s state.
A
A/T-labeling
Acronym for All Terrain. See “Off-road tires”.
Abrasion patterns
A specialist’s indicator for incorrect adjustments and overall damages at a car. It’s highly recommended to check a car’s condition after every 15.000 miles.
ABS
The Anti-lock Braking System is a safety system. Over a thousand of its steering impulses help to regulate the currently needed braking pressure. This mechanism helps preventing blocked tires. An improved maneuverability and a better track accuracy are the results of this system.
Additional fine balancing
Describes an essential procedure for a car’s steering axle. This practice is necessary in order to resolve residual unbalances.
Aging
Factors like humidity, varying temperature and UV radiation influence a tire’s aging. Some producers add different substances to the rubber compound in an attempt to slow down the process. The change of the currently used tires is highly recommended after a maximum use of eight years. In any case an e.g.: five year old spare wheel shouldn’t be used with completely new car tires.
Air loss
Air molecules leak out of the tires continuously. In order to prevent a flat tire air pressure should be checked every 14 days.
Air pressure
Most damages on a tire result from a shifted air pressure.
Airpumping
This phenomenon occurs when a tire is being pressed against the road with high pressure. Air goes through the many different thread channels which is leading to whistling and hissing sounds. It is possible to avoid most of those noises by an intent placement of the thread channels.
All season-tires
Definition for special tires, which can be used in summer as well as in winter.
All weather-tires
See all season tires.
Alloy wheel rims
Rims, which are made out of light alloy. Aluminum wheels weigh less than common steel wheels. They have improved road holding preferences and treat dampers and springs more careful.
Aluminium tires
See alloy wheel rims.
AM8, AM9, AMP, AMS, AMX-labeling
Label on tires for the car manufacturer Aston Martin, which can also be mounted on other vehicles.
Anti-theft bolt
Description of a special bolt, which is used to protect the rim against theft. It can only be removed with an individually manufactured wrench.
AO-labeling
Label on tires for the car manufacturer Audi, which can also be mounted on other vehicles.
AOE-labeling
Label on tires for the car manufacturer Audi, which can also be mounted on other vehicles. They are also equipped with Run-Flat properties.
Aquaplaning
Definition for the leafing effect on wet streets. Water creates a layer between the wheels and road surface. The result is a loss of traction and harder steering at mediocre speeds.
ASC
Acronym for Acceleration Skid Control. Name for a system to reduce blocking by transferring the exact amount of power a tire can endure without the loss of any traction.
Aspect ratio
Second number of the tire parameters.
Axis position
This indicator shows a specialist how a tire is being used. It’s important to inspect it every now and then because of the steering axle’s exposure to other forces than the drive axle. The drive type has to be kept in mind. The better pair of tires should always be on the rear axle.
B
Balancing
Necessary setting for the smooth run of a tire. Balancing weights get mounted at the right places to ensure the perfect stability on the road. This can be accomplished with the usage of so called balancing machines.
Bar
Name for the metric unit of pressure. It is used to measure a tire’s air pressure. Notes about the right pressure can be found in the car manual, the tank cap or the sun shield.
Bias-ply tires
Diagonal type of tires. Their cord threads got arranged transversely to their direction of movement.
BioTRED-labeling
Definition for environmentally-friendly tires from the producer Goodyear. Besides being manufactured from corn they also have better grip and less roll resistance.
Black Chilli Technology
Special rubber compound from the producer Continental.
BluEarth Technology
Special environmentally-friendly tires from the producer Yokohama.
Bolt circle diameter
Diameter between the wheel bolts and nuts.
Bolt pattern number
Number of bolts, which are used to mount the rim.
Brake assistant
Name for a progressive system, which is monitoring the driver’s actions in order to achieve safer and faster brakings.
Braking distance
Distance between the moment a driver can consciously recognize danger and the actual stop of a car. It depends on the driven speed of the car and the driver’s reaction time. The braking distance can increase due to old parts, extraneous impacts and distraction.
Braking flats
Name for flat-spotted tires. Vehicles without an anti-lock braking system can’t space out the power evenly during a panic stop, which leads to ruined car threads. Damaged tires should be replaced as soon as possible.
Bulge
Name for the inner ring of the tire sidewall. It allows the secure hold between a tire and rim.
C
C-tires
Special tires for commerical vehicle.
Calender
Name for a roll system. It’s used to coat cord threads with rubber.
Carcass
Most important part of the tire body. It is made out of multiple layers of rubber cord threads. These materials in combination with the right air pressure form a rugged tire.
CBC
Acronym for Cornering Brake Control. A improved version of the ABS. It carefully slows down every single wheel in curves to provide more safety on the road.
CD-labeling
Label for tires, which were produced in China.
Centering disk
The center bore hole gets set at the hub diameter of the car by adjusting it with a centering ring.
Commercial vehicle tires
Special tires for trucks, transporters and buses.
Conical collar
A certain type of bolt or nut. It has a cone-shaped screw guide.
Contact surface
The tire’s area which is currently touching the ground.
Cord-labeling
Label on tires for the car manufacturer Mercedes Benz, which can also be mounted on other vehicles.
Cord threads
Essential component needed for the production of new tires. These threads get implemented into the rubber compound and are mostly made out of rayon, nylon and polyester. Experts distinguish a bias-ply or radial tire on the basis of the threads.
CP-labeling
Identification for enhanced camping tires. They are similar to C-tires, but got strengthened to withstand higher weights with the help of increased air pressure.
D
D-labeling
Identification for cross-ply carcasses. The production of this tire type isn’t common nowadays but it can still be seen on oldtimers sometimes.
DA-tires
Tires with this identification have insignificant flaws. There is still a 100 percent guarantee on each tire and they do not have any technical defects.
Demo-tires
Dismantled tires from new vehicles. They weren’t used for a distance longer than 32 miles.
DOT number
Acronym for Department of Transportation.
Double hump
Two humps which can be found at the bead seat. Their acronym is “H2”.
Drainage
This French word is an indicator for driving safety on wet roads. Tires with a good drainage have the perfect grip under humid conditions.
Driving physics
A driving vehicle’s tires must resist many different forces. The most important of those are the engine power, centrifugal forces, braking forces and longitudinal forces.
Drop-centre rim
Special kind of rim with a low-lying rim base. The central part is lower compared to common rim types.
DSST-labeling
Acronym for Dunlop Self Supporting Technology. It is a name for tires from the manufacturer Dunlop with special Run-Flat properties.
E
Eagle-labeling
Name for wide range of high-performance tires from the producer Goodyear.
ECE test mark
The ECE test mark verifies the production of tires sticking to the EU-guidelines. It can be seen by looking at the letter “E” which is listed at the sidewall of the tire. The following letter identifies the country it was produced in.
ECOPIA-labeling
Energy-saving tires from the producer Bridgestone.
EDS
Acronym for Electronic Differential Lock. It assists the driver during the start-up by slowing down one driving wheel to avoid any blocking. At the same time the surplus energy gets shifted to the other driving wheel. Cars with a 4-wheel drive are suitable for the EDS-system in easy terrain. However brakes might be wearing off much quicker.
EMT-labeling
Acronym for Extended Mobility Technology. It identifies Run-Flat tires from producer Goodyear.
ENVIRON-labeling
Name for tires, which were produced for Scandinavian countries.
ESP
Acronym for Electronic Stability Program. Blocking wheels get prevented by activating the ESP in combination with the ABS.
F
F-labeling
Labels on tires for the car manufacturers Ford and Ferrari, which can also be mounted on other vehicles.
Firmness certificate
Report, containing the most important technical specifications of a rim. It shows all test it was put to and the results.
Flexing work
Definition for the deformation of a tire.
G
G-labeling
Label on tires for the car manufacturer Opel, which can also be mounted on other vehicles.
G1-labeling
Label on tires for the manufacturer Michelin, which must be mounted in pairs on each axle.
Grip
Synonym for the traction of a tire. It is an essential quality for good road holding.
H
Heel and toe wear
Special type of tire wear. The tire starts running irregularly with an arising “saw tooth wear” as a result. This can be the outcome of bad quality components, a rough style of driving, worn-out shock absorbers or a shifted axle geometry. The tire still stays usable but with negative side effects. Examples are steering wheel fluttering, a turbulent driving behavior and very loud tire noises.
High air pressure
High air pressure is as harmful for tires as low air pressure. Shock absorbers and driving comfort suffer as a result. Traction deteriorates and the tires tend to wear of irregularly.
High-Performance tires
Special tires for sports cars. Most of them have a directional pattern to increase traction.
Homologation
Name for the technical approval of a tire. The whole testing process is strictly monitored by car manufacturers. Approved tires are a strong indicator for the high quality of a tire.
Hump
A hump is located at the bead seat and tries to prevent the tire from moving. This can happen due to too low air pressure or increased load.
Hydrodynamic effect
Definition for increased water drainage due to arrow-shaped, directional profiles and improved channels.
I
Ideal tires
Other name for remoulded tires.
Improved wet grip
Rubber compounds get reinforced with silicate to make them more slip resistant on wet roads.
Inch
Name for a linear measure. It equals 2.54 centimeters.
Inner liners
Name for the rubber layer inside the interior of a tubeless tire. It enables an airtight seal on a tire’s inside.
Interlocking
Increases traction on snow-covered roads. Special edges on the entire tire provide the perfect grip by sticking the tires to the ground.
Intermediates
Name for racing tires with a hand-cut profile. They are quite suitable for wet and drying streets.
J
J, JRS-labeling
Label on tires for the car manufacturer Jaguar, which can also be mounted on other vehicles.
JP-labeling
Name for tires, which were produced in Japan.
K
K1, K2, K3, KA-labeling
Name for modern tire profiles with different rubber compounds and an improved design. Tires with this label shouldn’t be combined with older models. Markings from the producer Michelin label special tires for the car manufacturers Ferrari and Maserati. Tire producer Pirelli uses these labels to mark different profile designs and dimensions.
kPa
Acronym for kilopascal. It’s the measurement unit for air pressure. One bar equals one hundred kilopascal.
L
L-labeling
Label on tires for the car manufacturer Lamborghini, which can also be mounted on other vehicles.
Lateral forces
Impacts the car while driving along curves. It is not recommended to brake or accelerate in curves because of reduced longitudinal forces.
Legal minimum tread depth
Most European countries require a minimum profile depth of 1.6 millimeters. It must be measureable at the entire running surface. However summer tires should be changed at 2 millimeters and winter tires at 4 millimeters of profile depth on behalf of safety reasons.
Load index
Shows the maximum load capacity of a tire. For more informations, see at the following table below.
Klasse
U
H
V
VR
W
ZR
Y
km/h
200
210
240
>210
270
>240
300
Low rolling resistance tires
Tires with improved rubber compounds to counteract roll resistance. They have a lower fuel consumption too.
Light stabilizers
This product can be used to make tires more resistant against UV radiation.
LRO-labeling
Label on tires for the car manufacturer Land Rover, which can also be mounted on other vehicles.
LS-labeling
Label on tires for the car manufacturer Lotus, which can also be mounted on other vehicles.
LT-labeling
Improved tires for light commercial trucks like transporters.
M
M+S- or M&S-labeling
Tires with this special label were tested according to defined test criteria. This label can be seen on winter and all-season tires. It indicates proven performance on snowy and muddy roads.
M3-labeling
Label on tires for the car manufacturer BMW M3, which can also be mounted on other vehicles.
MC, MC1-labeling
Label on tires for the car manufacturer McLaren, which can also be mounted on other vehicles.
Manufacturer commitment
Back in the days some car manufacturers used to license only specified tires for their vehicles. Special vehicles like sport cars were forced to stick to W-, ZR-, and Y-tires (see “Speed rating”). This resolution was lifted in February 2000.
Matching
Special tire-mount procedure. It is required to insure ideal tire running. Concentricity deviations get combined perfectly to neutralize each other.
MFS-labeling
Label for tires with a special rim protector. It is basically an additional rubber lip.
MGT-labeling
Label on tires for the car model Maserati Quattroporte, which were produced as an original equipment.
Mixed tires
The combination of different tire types can cause loss of control while driving. The mounting of different tire sizes is forbidden by law in most European countries. The only exception occurs during the application of a spare wheel.
MO-labeling
Label on tires for the car manufacturer Mercedes Benz, which can also be mounted on other vehicles.
MOE-labeling
Label on tires for the car manufacturer Mercedes Benz, which can also be mounted on other vehicles. They are also equipped with Run-Flat properties.
N
N0, N1, N2 etc.-labeling
Label on tires for the car manufacturer Porsche, which can also be mounted on other vehicles.
New tires
New tires should be driven 150 miles. This procedure is recommended to rasp the tire’s tread adequately and activate their full potential.
Normal force
Definition of the force, which is pulling an object horizontally down to the support.
O
OE tires
Acronym for original equipment. Labels tires meeting the car producers’ specifications.
Off-road tires
Special tires, which were tested and produced for harder terrains.
Oversteering
This definition describes an increased impact during the steering process. The rear wheels start drifting which can cause the loss of control.
P
Part certificates
Rims with a part certificate must be registered. New rims might require car body work on account of larger and wider rim/tire combinations.
R
Radial run-out
Description of a deformed rim. It can be noticed while driving. The rims moving irregularly in this case.
Radial tires
Tires with cord threads in radial position. They are at right angle to the running direction.
Ramming damage
Definition for a specific type of damage, after a car tire’s bump against a hard surface like a curb. Rubber and carcass can be demolished during such an incident. In case of visible damage after a harder ramming, car tires should be replaced as soon as possible.
Rim
A car’s wheel without the tire.
Rim contour
It labels the rim type.
Rim diameter
Indicator for the rim’s size. It is measured in inch.
Rim flange
Name for a rim’s curved outlet.
Rim shoulders
Stabilisation for the wheel base. Ensures the right fit in combination with the flange.
Rim width
Distance between the rim flanges.
Recutting
Tires for commercial vehicles can be recut until the bottom of the profile has been reached.
Remix-labeling
Remanufactured tires from the producer Michelin.
Retread-labeling
Marks a tire with a new tread placed on the old carcass.
RF-labeled tires
Indication for reinforced car tires with higher carrying capacity.
Rubber
Main component during the production of new tires. Most of today’s producers use synthetic rubber instead of natural one.
RFT-labeling
Label on tires from the producer Bridgestone with Run-Flat properties.
RO1-labeling
Label on tires for the Audi Quattro series, which can also be mounted on other vehicles.
ROF-labeling
Acronym for Run On Flat. Marks tires from producer Dunlop with special Run-Flat properties.
Rolling resistance
Designates the resistance of the motion of a body witch is rolling on a surface. In relation to car tires this phenomenon is also called flexing work (See “Flexing work”).
RPB-labeling
Acronym for Rim Protection Bar. It indicates a rim protected tire from the producer Yokohama.
RPB-labeling
Tires, which were produced in South Africa.
Rubber compound
Tires can be fabricated with up to 16 different rubber compounds. The exact chemical structure however stays a secret.
Run-flat tires
Special tires with an emergency mode that can be used even they have lost all air pressure. In punctuated state the tires can be driven at 50 m/h for about 50-100 miles to reach the next garage.
Running direction
Most tires have a dictated running direction. It is usually mentioned on the side of tire with an arrow or the word “rotation”. Tires with a clear running directions have many advantages like a reduced noise level, improved wet-weather performance and better grip at snow-covered and frozen roads.
Running performance
The running performance of a tire largely depends on right mixture of the rubber compound and the driver’s behavior.
Running surface
Part of the tire which is touching the underground.
S
S-labeling
Label for low-noise tires which meet certain EU directives. The S is an acronym for “sound”.
S1-labeling
Label on tires for the car manufacturer Peugeot, which can also be mounted on other vehicles. They are also equipped with Run-Flat properties.
Severe snow-labeling
See “Snow flake symbol”.
Shoulder wear
Unilateral shoulder wear will occur if the tire’s position isn’t arranged perfectly on the road. Double-sided shoulder wear happens due to too low air pressure. Reckless driving and a high number of curves on the road can also lead to increased shoulder wear.
Sidecar
Name for an additional second bike seat. It has another wheel.
Side wall
It is also called flange. Most of the tire designations and other indications are mentioned there.
Silicate
Component, which is used during tire production. It ensures a better grip on wet roads and a reduced roll resistance at the same time.
Single piece rim
Rim made out of a single cast.
Slick tires
Name for tires without any profile. They are mostly used in motorsport.
Slip
Definition for the relative motion between a tire and the surface it’s moving on. A 100 percent slip means wheel blocking. The slip’s extend depends on brake and motive power. It is not possible to avoid slipping completely. This is the main reason for tire wear.
SmarTRED-labeling
Name for innovative concept, which is providing good traction in all seasons. This technology is a combination of different tire characteristics including solid shoulder blocks, an efficiently laminated center and special ground contact areas ensuring a flexible adaption to changing roads. Vector 5 tires from the producer Goodyear use this concept.
Snow chains
Some roads are impassable after heavy snowfall. In order to counteract this situation snow chains can be mounted at the sidewalls of the drive wheels. The results are the reduction of spinning wheels and a continued journey on slippery roads.
Snow flake symbol
The snow flake symbol represents a kind of quality seal for quite some time now. In order to be wearing this symbol wheels have to pass several special and intensive tests. The snow flake symbol with a mountain shows sustainability of the tires at severe weather conditions.
Spare wheel
Name for the fifth wheel inside the car. It gets used in case of puncture.
Speed capability
High-performance and ultra-high-performance tires get tested in special facilities to ensure sufficient road stability.
Speed rating
Every tire has a permissible maximum speed, which is marked with a certain letter. These can be found in the following table below.
Klasse
L
M
N
P
Q
R
S
T
km/h
120
130
140
150
160
170
180
190
Klasse
U
H
V
VR
W
ZR
Y
km/h
200
210
240
>210
270
>240
300
Speed index
See “Speed rating”.
Spherical collar
A certain type of bolt or nut. It has a spherical screw guide.
Sprocket wheels
Wheel spacers are used to widen the car track. They are installed between the rim and axle.
SSR-labeling
Labels tires with Run-Flat properties.
Star-labeling
Label on tires from the producer BMW, which can also be mounted on other vehicles.
Steering precision
This phrase describes the extent of the ability, to steer a tire as precise as possible.
Steering wheel vibrations
Badly balanced tires are the most common reason for this behavior. It can be avoided by matching and the replacement of missing or damaged balancing weights.
Studable-labeling
Indicator for studable tires. See “Studded tires”.
Studded-labeling
Indicator for studded tires. See “Studded tires”.
Studded tires
Tires with metal studs on their running surface. They are used to improve traction on snow-covered and frozen roads.
Sulphur
Main component during tire production. The addition of Sulphur increases interconnection between rubber molecules during the vulcanization process. Elastic rubber forms out of the plastically-sticky material subsequently.
Summer tires
Tires for dry and humid roads as well as high speeds.
T
TCS
Acronym for Traction Control System. The engine’s power gets regulated in order to avoid tire slipping. It is an essential part of the Acceleration Skid Control.
Three-piece rim
This type of rim consists of two wheel halves and the wheel center.
Tire designation
The most important designations are imprinted on the edge of the tire. See the following image below.
Tire dimensions
The right tire dimensions for your car are visible on the tire’s sidewall.
Tire pressure
Definition for the tire’s air pressure. It is measured in bar. See “Bar”.
Tire pressure control system
This system allows the driver to monitor the current air pressure via display. It has the ability to warn the driver of sudden air loss.
Tire profile
The tire’s main component for traction. A high number of voids and open blocks create the ideal running surface for snow and mud. Slick tires are theoretically the best for dry and flat grounds.
Tire sidewall
Definition for the tire’s side wall.
Tire size
Indication for a wheel’s width, aspect ratio and rim diameter. It can be seen on the edge of the tire.
Tire structure
A tire is made out of different materials. The running surface, the sidewall and tire bead are visible on the outside of the tire.
TL-labeling
Acronym for tubeless. See “Tubeless”.
Track
This term defines the position of the left and right wheel to each other. It determines whether they are parallel, converging or diverging. Knocked out suspension and steering parts can be the cause. Increased tire wear arises from these issues.
Traction
This definition describes a car’s ability to stick the engine power to the road with the least amount of tire slipping. Traction on a dry road might not be an issue but driving on wet, snow-covered or frozen roads certainly is. The composition of the rubber compound and the tire profile are two essential factors influencing the traction of a car.
Trailer tires
Trailer tires are tougher than common vehicle tires because they were made of heavy duty materials. Trailers which are not used explicitly during summer should be mounted with winter or all-season tires.
Tread compound
The right combination of materials can reduce noises and improve the general running performance of the tread compound.
Tread wear indicator
This indicator shows the difference between a new and a bald tire. Most tread wear indicators are labeled with the acronym TWI.
Tubeless tires
The first tubeless tire was invented in 1943. It became a matter of course these days.
TWI
Acronym for Tread Wear Indicator. See “Tread Wear Indicator”.
Two-piece rim
This type of rim consists of two different parts: the wheel barrel and the wheel centre.
U
ULW-labeling
Tires with label (ger.: Ultra-Leicht-Bauweise) are only mountable on cars from the producers VW and Audi.
Understeering
This definition describes a reduced impact during the steering process. The front wheels start drifting which can cause the loss of control.
Uniformity
Another word for the production accuracy of a tire. It is essential for perfect and quiet driving. A high uniformity allows a specialist to balance a tire perfectly.
V
Valve
There are two different types of valves: the rubber- and the metal valve.
Valve cap
Cap, which is protecting the valve from dirt and humidity. It is an essential part of the impermeability of the tire-wheel-system.
Valve tearing
Cause for eminent pressure loss in the tires.
Vector
Collective name for all-season tires from the producer Goodyear.
VTS-labeling
Acronym for Variable Thickness Sipe. It is a name for high-performance tires. They have special self-locking edges with optimal transmission, handling and steering precision.
Vulcanization
Name for the last step during the tire production. The final tire form is being created in the vulcanizing press. It is important to choose the right pressure, temperature and processing time to create the perfect type of rubber. The process takes place at temperatures of 165 to 200°C, a pressure of 12 to 24 bar and it last for about 9 to 17 minutes.
W
Water displacement
Definition for the water drain between the drainage grooves of the positive blocks of the tire.
Wear
Aging and constant running performance cause tire wear. The ratio depends on the air pressure and the style of driving.
Wheel bolt
Connection between rim and car. There are two different types of bolts: conical and spherical bolts.
Wheel-change
Wheels should be switched from one axle to the other after every 10.000 miles. New tires should always be mounted on the rear axle regardless of the drive system.
Wheel disc
Connection between the rim and the wheel hub.
Wheel load
Determines the maximum load capacity of each axle. It is declared in the vehicle registration. Regarding this indication is very important.
Wheel movement
Tires always need enough space between the body and the braking system in order to avoid damages.
Wheel offset
Distance between the flange and the rim center.
Wheel rim
See “Rim”.
Wheel rim labeling
Rims are labeled with different symbols and acronyms. These can be seen at the rim itself.
Wheel rim structure
See the following image below.
Winter tires
Winter tires have a better traction than sommer tires on snow-covered roads because of many lamellas and negative blocks. Their special rubber compound counteracts hardening of the running surface at low temperatures.
Wrench size
Definition for the size of tire changing tools. They are used to loose wheel bolts or nuts. The most common sizes are 17, 19 and 21 millimeters.
X
XL tires
Name for reinforced heavy duty tires, with a single-layered base and an improved carrying capacity.
Z
ZP-labeling
Label on tires from the producer Michelin, which can also be mounted on other vehicles. They also have Run-Flat properties.
