道路標識メキシコ

Tyres are the vehicle's contact with the road and transmit the forces required for steering, acceleration and braking. Their condition and available grip therefore directly affect vehicle control.

Regularly check tyre pressure, tread depth and general condition. Look for excessive or uneven wear, cuts, cracks, bulges or other damage and replace tyres when they are no longer safe or legally compliant.

Requirements vary between countries, but tyres fitted to the same axle should be compatible in dimensions, construction and performance. National rules may impose specific matching requirements.

205 indicates the nominal tyre width in millimetres, 55 is the aspect ratio between sidewall height and tyre width, R indicates radial construction and 16 indicates the diameter of the wheel rim in inches.

The number is the load index, which identifies the maximum load the tyre is designed to carry under specified conditions. The letter is the speed rating or speed-category symbol, which indicates the tyre's approved speed capability.

Tyres can carry additional markings indicating approval, manufacturer information, production date, suitability for winter conditions, reinforced construction or other technical characteristics. The exact markings depend on the tyre type and applicable standards.

Winter tyres use tread patterns and rubber compounds designed to provide better performance in cold temperatures, snow and other winter conditions. Summer tyres are optimised primarily for warmer conditions.

The Three-Peak Mountain Snowflake symbol identifies a tyre that has met specified performance requirements for use in severe snow conditions. It provides a more specific indication of tested snow performance than an M+S marking alone.

No. Some countries require winter tyres during particular months or whenever winter conditions occur, while others have no general requirement. Drivers travelling abroad should check the rules of every country on their route.

Correct tyre pressure helps provide predictable handling, braking and tyre wear. Incorrect pressure can reduce performance, increase tyre wear and increase fuel consumption.

Use the pressure specified by the vehicle manufacturer rather than the maximum pressure marked on the tyre. The recommended values can normally be found in the vehicle handbook or on a vehicle information label.

Yes. Tyres gradually lose air over time, so their pressure should be checked regularly and before demanding or long journeys. The pressure should be adjusted to the manufacturer's recommended value.

Snow chains increase traction when driving on roads covered with snow or ice. They can help a vehicle accelerate, steer and brake where ordinary tyre grip is insufficient.

Snow chains are normally fitted to the driven wheels, but the correct arrangement depends on the vehicle and its drivetrain. Drivers should follow the vehicle and chain manufacturer's instructions.

No. Requirements vary between countries and roads. Some countries require chains to be carried during certain periods or fitted when indicated by traffic signs or winter conditions, while others impose no general requirement.

Bicycle tyres provide the grip needed for steering and braking and help absorb irregularities in the road surface. Worn, damaged or incorrectly inflated tyres can reduce control and increase the risk of a puncture or loss of grip.

Check the tyre for adequate pressure, excessive tread wear, cuts, cracks, bulges and objects embedded in the tread. The tyre should also be correctly seated on the rim.

No. Tyre width, diameter, tread and construction vary according to the bicycle and its intended use. Road bicycles commonly use relatively narrow tyres, while mountain bikes generally use wider tyres with more pronounced tread.

Continuous tracks provide traction and distribute a vehicle's weight over a larger contact area than conventional wheels. They are particularly useful on mud, snow, loose soil, construction sites and other difficult terrain.

Tracks can consist of linked metal sections, continuous rubber belts or systems combining metal and rubber components. The design depends on the vehicle and its intended operating conditions.

Some tracked vehicles can use public roads when they meet the applicable vehicle, registration and road-use requirements. Restrictions may apply because certain track designs can damage road surfaces or because the vehicle has unusual dimensions, weight or speed characteristics.

Gross Vehicle Weight includes the weight of the vehicle itself together with the driver, passengers, fuel, luggage, cargo and other items being carried at that moment.

GVW is the vehicle's actual weight at a particular moment. GVWR is the maximum total weight the vehicle is designed or legally permitted to have when loaded. The actual GVW must remain within the applicable maximum.

Vehicle weight affects braking, handling, tyre and axle loading and legal weight limits. Overloading can reduce safety and may also cause the vehicle to exceed permitted axle or total-mass limits.

GVWR represents the permitted maximum total weight of the loaded vehicle, including the vehicle itself, driver, passengers, fuel, luggage, cargo and other equipment carried by the vehicle.

GVWR is the maximum permitted or rated weight of the vehicle, while GVW is its actual weight at a particular moment. The GVW changes as passengers or cargo are added or removed, while the GVWR remains a fixed limit.

GVWR determines how heavily a vehicle may be loaded and can affect driving-licence categories, vehicle classification and other legal requirements. Exceeding the permitted maximum can also adversely affect braking, handling, tyres and other vehicle components.

Unsecured cargo can move during acceleration, braking or cornering and can affect vehicle stability or fall onto the road. Proper securing protects the occupants, other road users and the cargo itself.

Yes. Heavy or poorly distributed cargo can change the vehicle's centre of gravity, braking distance, steering and stability. Loads should therefore be distributed appropriately and kept within the vehicle's permitted limits.

In some circumstances it can, but national rules normally limit how far a load may project beyond the front, rear or sides of a vehicle and may require projecting loads to be specially marked.

The car body is the structure and exterior bodywork surrounding the vehicle's occupants and cargo areas. It includes visible panels as well as structural sections that can contribute to the strength of the vehicle.

Not always. In some vehicles the body is mounted on a separate chassis or frame. Most modern passenger cars use a self-supporting body in which much of the body structure also performs the structural function traditionally provided by a separate chassis.

The body helps protect occupants and supports many vehicle components. Serious corrosion, deformation, loose panels or structural damage can reduce crash protection or create hazards for other road users.

A trunk is primarily used for carrying luggage and other cargo separately from the passenger compartment. Its size and location depend on the vehicle's design.

Yes. Heavy or loose objects can move during sudden braking, acceleration or cornering. Cargo should therefore be positioned and secured so that it cannot affect vehicle stability or cause injury.

No. The combined weight of the vehicle, occupants and cargo must remain within the vehicle's permitted total and axle-load limits. Excessive loading can adversely affect braking, steering and stability.

A suitable roof rack can carry items such as luggage boxes, bicycles, skis and other equipment, provided the rack and attachments are designed for the load and the vehicle's permitted roof-load limit is respected.

Yes. Weight carried high on the vehicle raises its centre of gravity and can affect stability, particularly during cornering or sudden manoeuvres. Drivers should secure the load carefully and adapt their driving accordingly.

Check the vehicle manufacturer's specifications and the limits of the roof rack itself. The permitted load can vary significantly between vehicles, and the lowest applicable limit should not be exceeded.

The windscreen allows the driver to see the road ahead while protecting vehicle occupants from wind, rain, insects, stones and other debris.

Yes. Cracks, chips or deformation can interfere with the driver's view and may weaken the windscreen. Damage in the driver's main field of vision is particularly important and should be repaired or assessed promptly.

Windscreen wipers remove rain, snow and dirt from the driver's viewing area. A clear windscreen is essential for maintaining adequate forward visibility in poor weather.

An emergency hammer is used to break a suitable vehicle window so occupants can escape when normal doors or emergency exits cannot be opened.

In vehicles equipped with them, emergency hammers are normally mounted in an easily accessible position close to an emergency window or other designated escape point.

No. Vehicle windows can use different types of glazing, and not every window is designed to be broken as an emergency exit. Occupants should use designated emergency windows and follow the instructions provided in the vehicle.

A car battery stores electrical energy, supplies the power required to start the engine and supports the vehicle's electrical and electronic systems when necessary.

Possible signs include slow engine cranking, difficulty starting, dim or unstable electrical equipment and battery or charging-system warnings. Similar symptoms can also have other causes, so the charging system may need to be checked.

No. The battery must have specifications and technology suitable for the vehicle. Cars equipped with start-stop systems, for example, may require AGM or EFB battery technology designed for repeated starting and charging cycles.

A traction battery stores electrical energy and supplies it to the electric motor or motors that propel the vehicle. In hybrid vehicles it works together with another power source, while in battery-electric vehicles it provides the main source of propulsion energy.

The traction battery provides the large amount of electrical energy needed to propel the vehicle. The conventional 12-volt battery mainly supplies low-voltage systems and supports functions such as vehicle electronics, control systems and starting procedures.

Battery capacity indicates how much electrical energy the battery can store and is commonly expressed in kilowatt-hours (kWh). A larger usable capacity generally allows more electrical energy to be available for driving.

The suspension supports the vehicle, allows the wheels to move over uneven surfaces and helps keep the tyres in contact with the road while controlling body movement.

Common suspension components include springs, shock absorbers or dampers, control arms, bushings, ball joints and other links connecting the wheels to the vehicle structure.

Possible signs include excessive bouncing, unusual noises, poor stability, uneven tyre wear, excessive body movement in bends or a vehicle that sits unevenly. These symptoms should be inspected because they can also have other causes.

A shock absorber controls suspension movement by damping the repeated movement of the springs. This helps stabilise the vehicle and maintain tyre contact with the road.

Possible signs include excessive bouncing, increased body movement, poor stability, unusual suspension noises, uneven tyre wear or visible fluid leakage from the shock absorber.

No. Springs support the vehicle and allow the suspension to move over bumps, while shock absorbers control and damp that movement. The two components work together as part of the suspension system.

A suspension spring supports the vehicle and allows the wheels to move over uneven surfaces while helping maintain the vehicle's normal ride height.

Common designs include coil springs, leaf springs, torsion bars and air springs. The type used depends on the vehicle and suspension design.

Possible signs include an uneven ride height, unusual suspension noises, poor handling or a visibly cracked or broken spring. A suspected spring defect should be inspected promptly.

The exhaust system carries combustion gases away from the engine and directs them out of the vehicle. It can also reduce exhaust noise and use emissions-control equipment to reduce pollutants.

Possible signs include unusually loud exhaust noise, rattling, visible damage, unusual exhaust smells, warning lights or emissions problems. A suspected leak should be inspected promptly.

Depending on the vehicle, the system can include an exhaust manifold, pipes, silencers, catalytic converters, particulate filters, sensors and other emissions-control components.

Exhaust gas contains products of fuel combustion and can include carbon dioxide, water vapour, carbon monoxide, nitrogen oxides, unburned hydrocarbons and particulate matter. The quantities depend on the engine, fuel and emissions-control system.

Some exhaust components, including carbon monoxide, nitrogen oxides and fine particles, can harm human health or contribute to air pollution. Exhaust should therefore never be allowed to accumulate in an enclosed space.

Vehicles can use technologies such as catalytic converters, particulate filters and electronic engine-management systems to reduce pollutants. Emission standards also limit the amount of certain pollutants that vehicles may produce.

Soot is produced when fuel does not burn completely. Diesel engines can produce particularly significant amounts of particulate matter, especially when combustion or emissions-control systems are not functioning correctly.

A diesel particulate filter traps a large proportion of the soot particles in the exhaust. The filter periodically removes accumulated material through a process known as regeneration.

Yes. Unusually high soot emissions can result from engine faults, poor combustion, a defective particulate filter or other problems with the emissions-control system.

A catalytic converter reduces harmful pollutants in engine exhaust by converting them through chemical reactions into less harmful substances before they leave the exhaust system.

It is installed in the exhaust system between the engine and the exhaust outlet. Its exact position varies between vehicles and may be relatively close to the engine so that it reaches its operating temperature quickly.

Possible signs include an emissions or engine warning light, excessive exhaust emissions, reduced engine performance, unusual exhaust smells or failure of an emissions test. These symptoms can also have other causes and should be diagnosed properly.

An engine converts energy into mechanical power that can be used to drive the vehicle's wheels. Internal-combustion engines obtain this energy by burning fuel, while electric vehicles use electrical energy in traction motors.

Possible signs include unusual noises, loss of power, excessive smoke, overheating, fluid leaks, difficult starting or an engine warning light. These symptoms can have many different causes and should be investigated when necessary.

Maintenance helps keep lubrication, cooling, fuel, ignition and emissions systems working correctly. Following the manufacturer's service requirements can improve reliability and help prevent serious mechanical damage.