The high temperatures put a strain on vehicle handling. Stability, grip and handling may be affected when the thermometer climbs. To ensure safe driving during heatwaves, several key elements must be monitored : tires, suspensions, shock absorbers and electronic driving assistance systems. Discover the essential tips to optimize your car’s handling when temperatures are high.
What is the road holding of a car ?
Technical definition and basic principles
The ability of a vehicle to maintain its trajectory is based on complex physical principles. This depends in particular on the weight distribution between front and rear, as well as on the position of the centre of gravity.
An optimal wheelbase combined with well-adjusted rolling stock ensures maximum stability in turns. The interaction between the wheels and the road plays an important role : the larger the contact surface, the better the directional control.
Electronic devices such as ESP (Electronic Stability Program) or ASR (Anti-Slip Regulation) complement these mechanical aspects. These technologies continuously analyze the vehicle’s behaviour to correct its trajectory in case of drift or understeer.
The importance of driving behaviour
Optimal driving behaviour ensures a safe and pleasant driving experience. The perfect control of the vehicle allows to anticipate dangerous situations and avoid accidents. For example, during an emergency brake application on a wet road, a well-adjusted car will maintain its course without deflecting.
Vehicle dynamics play a central role in passenger comfort. Good road handling effectively absorbs road surface irregularities, reducing fatigue during long journeys. Car manufacturers adapt their settings according to the intended use: sporty for performance sedans, comfortable for families.
A stable vehicle gives the driver confidence and allows him to remain calm in changing weather conditions or unforeseen situations on the road.
The essential components of rolling stock
The crucial role of shock absorbers
Shock absorbers convert mechanical energy into heat to control the oscillations of the vehicle. This conversion maintains a permanent contact between the wheels and the road, especially during summer temperature changes.
A high-performance damping system regulates the vertical movements of the body. Hydraulic or gas models absorb shocks while their internal fluid dissipates the heat generated by road impacts.
During high temperatures, the viscosity of the damping fluid changes. Gas-fired shock absorbers have an advantage in this case due to their better resistance to high temperatures. This technology ensures constant vehicle stability, even when the mercury rises.
Suspensions and their impact
The coil springs and torsion bars in the suspensions are subjected to a high load when the mercury rises. Heat changes their mechanical properties, directly affecting the driving behaviour of the vehicle.
An adjustment adapted to the summer conditions is essential. Suspension that is too soft can cause excessive rolling in fast turns, while suspension that is too firm reduces grip on heat-warped surfaces.
The height of the vehicle also plays a decisive role : optimum ground clearance ensures maximum stability even at high speeds. Manufacturers recommend regular testing of suspensions during periods of high heat to maintain performance and safety.
The importance of stabilizers
The stabilizer bars act as true balance guards for your vehicle, especially when you make sudden changes of direction. Their action is crucial when the mercury climbs, as they compensate for the pressure on the outer wheels in the turns.
As an example, on a 35°C winding road, these bars work in synergy with the shock absorbers to keep all four wheels firmly anchored to the ground. This collaboration significantly reduces the risk of wheel detachment and spillage in turns.
Extreme heat can change the mechanical characteristics of stabilizer bars. Regular checks are required to ensure their proper functioning and prevent any deterioration in driving comfort.
The ball joints and suspension triangles
Suspension ball joints provide a mobile link between the chassis and wheels, allowing for smooth and controlled movement. The rise in temperature puts these mechanical components to a particular test, as their lubricating grease undergoes a gradual transformation.
The suspension triangles maintain the geometric alignment of the wheels in all conditions. Their aluminium or steel design gives them resistance to extreme thermal variations. A regular diagnosis is required to check the condition of the silentblocs, these rubber buffers that absorb vibrations.
Premature wear of these elements is manifested by metallic noises on the retarders or a marked directional drift. The safety of passengers depends directly on the good condition of these central parts of the rolling stock.
Tires : keys to good grip
The optimal pressure in hot periods
Tire pressure requires extra attention during the summer. A rise of 10°C results in an average increase of 0.1 bar in your tires. This variation may seem small but is crucial for your safety.
Measure the pressure only on cold tires, before any trip or after a prolonged stop of at least 2 hours. A morning check will give you the most reliable values.
The gum reacts differently depending on the outside temperature. Maintain the pressure recommended by the manufacturer to ensure maximum traction and preserve your tires’ service life. On the highway or during a heavy load, add an extra 0.3 bar to compensate for thermal stress.
The choice of gums according to temperature
Silica compounds in modern tyres provide exceptional stability up to 85°C. This technical innovation significantly improves grip on the hot roads of southern France.
A summer tyre is distinguished by its rigid structure, specially designed to resist the deformation caused by heat peaks. Its unique composition allows it to maintain its optimal performance above 7°C, unlike winter gums that lose their effectiveness at this temperature.
Premium manufacturers now offer sophisticated blends that combine strength and flexibility. This advanced technology ensures better ground contact distribution, even when the asphalt reaches extreme temperatures during the summer season.
The impact of wear on adhesion
The depth of the carvings plays a decisive role in road safety. A worn-out tread drastically reduces the ability to evacuate water and increases the risk of aquaplaning, even in dry weather.
A tire with wear of up to 2 mm requires a 15% longer braking distance than a new tire. This difference is more pronounced on wet roads where the risk of loss of control becomes greater.
Manufacturers recommend replacement as soon as the depth reaches 3 mm to maintain optimal hold in all circumstances. A regular check of the wear indicators makes it possible to anticipate this critical limit and guarantee maximum grip, especially during high temperatures where the road becomes more slippery.
Electronic driver assistance systems
The ESP and its stabilizing role
The electronic trajectory corrector analyzes in real time the movements of the vehicle thanks to its sophisticated sensors. This technology monitors wheel grip and instantly detects deviations between the direction desired by the driver and the actual trajectory.
In the event of understeer or loss of grip, ESP applies targeted braking to each wheel. The system also modulates engine power to restore vehicle stability.
A prime example : during an emergency bypass at 130 km/h on the highway, the ESP brakes the inner rear wheel to counteract the start of skidding and maintain the desired heading. This precise intervention takes place in milliseconds, much faster than human reflexes.
Traction control in difficult conditions
Traction control is particularly valuable when starting on slippery or wet roads. This intelligent system regulates the power transmitted to the drive wheels to maintain maximum grip.
On uneven or unstable ground, the traction control instantly adapts its action. A sensor analyzes the rotational speed of each wheel and automatically limits the engine torque when slippage is detected.
The latest generations of traction control incorporate a self-adaptive function that adjusts its parameters according to the type of surface. This technology allows you to optimize traction on various terrains such as gravel, mud or melted snow. A major asset to keep control of your vehicle in the most demanding situations.
The trajectory sensors
Next-generation sensors now incorporate cutting-edge technologies for real-time monitoring of vehicle behaviour. Using sophisticated algorithms, these devices precisely measure lateral and longitudinal accelerations.
A network of electromechanical micro-systems strategically placed on the rigid axles analyses the movements of the chassis. This configuration allows ultra-fast detection of variations in contact with the ground on bumps, particularly useful during high temperatures where the asphalt becomes more loose.
Instant data transmission to the CPU ensures optimal system responsiveness. The small size of these sensors makes it easy to integrate them discreetly into the vehicle architecture, without compromising their performance or reliability.
How do you know if your car is holding up ?
Signs of poor handling
Several symptoms reveal a deterioration in the grip of your car, especially in hot weather. A steering wheel that vibrates abnormally during acceleration or a vehicle that pulls to one side for no apparent reason are warnings not to be ignored.
Unusual noise from the wheels during turns or excessive responsiveness to road surface irregularities also signals a potential problem. The jerks felt in the steering wheel during braking also deserve your full attention.
The sensation of an unusual floating at high speed or a direction that has become harder than usual are additional clues. In hot weather, these phenomena are often accentuated on roads deformed by extreme temperatures.
The avoidance tests to be carried out
The bayonet test is a reference for assessing your vehicle’s handling. On an open road, make a quick lane change at 50 km/h and then return to your original lane. This maneuver reveals the responsiveness of your car.
A second exercise consists of sequential slalom turns between markers spaced 20 meters apart. This test allows the analysis of mass transfer and directional accuracy.
On an empty parking lot, also test the braking stability : accelerate to 40 km/h then brake hard. The vehicle must maintain its course without deflection. These practical exercises will give you a clear view of the dynamic capabilities of your car in high heat.
The importance of professional diagnosis
A complete assessment by an expert makes it possible to identify anomalies that are invisible to the naked eye. Mechanics have sophisticated equipment to measure the condition of critical components of the rolling stock.
Specialized automotive centers use state-of-the-art test benches. These tools analyze the geometry, check the wear of parts and evaluate the reactivity of electronic assistance systems.
A careful inspection of the chassis often reveals micro-cracks or deformations caused by thermal expansion of materials. A preventive diagnosis before the summer season anticipates potential failures and guarantees maximum safety during long journeys under extreme temperatures.
The best cars in road styling
The ranking of sports sedans
German sports sedans dominate the market with their ultra-rigid chassis and exemplary behavior. The BMW M3 Competition stands out for its exceptional traction, even on winding roads at 35°C.
The Audi RS5 shines with its Quattro transmission, which distributes power optimally between all four wheels. This technology ensures outstanding road holding, particularly appreciated during the hot summer.
The Mercedes-AMG C63 impresses with its active roll control system, which guarantees perfect stability in fast turns despite road deformations. Its Asian rival, the Lexus IS 500 F Sport, impresses with its natural balance and directional precision, even on hot asphalt.
The best performing SUVs
High-performance SUVs redefine the dynamic driving standard. The Porsche Cayenne GTS excels in handling tight turns thanks to its adaptive chassis, while the BMW X5 M Competition displays remarkable agility despite its imposing size.
The Lamborghini Urus sets a new benchmark with its lightning-fast acceleration from 0 to 100 km/h in 3.6 seconds. Its air suspension automatically adjusts the ground clearance according to road conditions, guaranteeing optimal stability even under 35°C.
Range Rover Sport SVR’s state-of-the-art technologies enable intelligent wheel torque distribution, ensuring maximum grip on dry roads and slippery surfaces. His precise steering and powerful braking complement his exceptional sporting abilities.
City cars with exemplary behaviour
The Peugeot 208 is a reference in its category with remarkable stability on all types of roads. Its rigid chassis and precise steering give it a healthy behavior, even in hot summer weather.
The Volkswagen Polo demonstrates its driving qualities through a perfect balance between comfort and dynamism. Its specially calibrated suspension effectively absorbs road deformations, while its wheels adhere perfectly to overheated asphalt.
The Renault Clio scores points with its particularly efficient dynamic control system. Its behavior remains neutral and predictable, a major safety asset when mercury rises. The Ford Fiesta seduces demanding drivers with its exceptional traction and responsiveness, especially on winding roads in warm weather.
How to have a good road holding ?
The adjustment of geometry
Precise geometry adjustment is a key factor in maintaining excellent road handling in hot weather. Extreme heat changes the natural angles of the wheels, directly affecting vehicle stability.
Checking the camber and flush angles becomes important when the mercury rises. These technical parameters ensure an optimal contact surface between the tires and the overheated road. The millimetric adjustments made to the parallelism compensate for the deformations caused by high temperatures.
A regular control allows to anticipate the geometric deviations related to thermal variations. Electronic angle measurement reveals micro-deviations before they impact your safety on the road.
Optimisation of rolling stock
Train components require special attention during heat waves. A monthly control of the silent blocks and joints allows to anticipate their premature wear caused by extreme temperatures.
The addition of polyurethane-reinforced rings to the anchor points of the suspension arms significantly reduces heat-related deformations. This modification increases the stability of the vehicle on roads distorted by the sun.
High performance oil dampers are more resistant to thermal variations. Their specific technology maintains a constant viscosity up to 40°C, ensuring optimal control of crate movements. Regular greasing of the front-wheel joints preserves their flexibility even in extreme heat.
Possible modifications of the chassis
The anti-match bars represent a first accessible modification. Installed between the shock absorber turrets, these metal reinforcements limit the deformation of the chassis during lateral stresses, especially on winding roads at 35°C.
The addition of underfloor shell reinforcements improves overall structural rigidity. This modification, particularly appreciated on sports sedans such as the BMW M3, reduces parasitic vibrations when the asphalt reaches high temperatures.
Aluminum-reinforced suspension triangles reduce unsuspended weight while increasing directional accuracy. A concrete example : the Honda Civic Type R uses this technology to maintain optimal contact with the road, even on track in high temperatures.
Maintaining good handling in hot weather requires special attention to all the components that connect your vehicle to the road. Tires, suspensions, shock absorbers, geometry and electronic driving aids all play a critical role, especially when temperatures exceed 30°C.
A regular check of these elements, combined with adjustments adapted to the summer season, allows to maintain an optimal stability, to improve the reactivity of the vehicle and to limit the risks related to road deformations. Whether you’re driving in the city, on the highway or in mountainous areas, every detail counts for your safety and comfort.
Taking care of your car’s handling in summer means not only anticipating heat-related wear and tear, but also ensuring that your vehicle remains efficient, reliable and pleasant to drive throughout the season. For peaceful journeys under the sun, proper care makes all the difference.
