DRY BRAKING

Drivers don’t practice emergency stops – when you need to perform one you need to know that your car will halt in a safe and composed manner.

A dry braking test consists of driving a vehicle at high speed, then applying the brakes.

The distance covered by the car when coming to a complete stop is measured by ultra-precise GPS equipment.

WET BRAKING

Stopping quickly, smoothly and safely on rain-soaked roads with little traction is a vital safety feature of tyres.

A wet braking test consists of driving the vehicle at high speed and then applying brakes.

The distance covered by the car when coming to a complete stop is measured by ultra-precise GPS equipment.

DRY HANDLING

Dry handling performance should exceed all normal driving requirements.

In our testing we grade performance parameters across four categories:

• Ride
• Steering
• Stability
• Noise

Tests are conducted both at high speed – pushing the tyres beyond the limit of their grip – and also at typical driving speeds over a range of controlled surfaces and bumps. Dry handling is not all about high speed performance. Top lap times are not relevant on dry roads. Tyres should provide safety reserves when taken to their limit and their road performance should be effortless and predictable since this helps a driver to relax and avoid driving errors. For this purpose, the test driver evaluates the reaction to steering input and cornering as well as rear axle stability. They look for how tyres react to changes in direction and pace, the amount of steering lock required and for any loss of grip to be progressive.

WET HANDLING

Wet roads bring most drivers as close as they will ever get to the limit of their tyres’ capability. The drastic reduction of natural surface grip caused by rainfall can expose significant performance differences between tyres.

Wet handling testing consist of both objective and subjective tests.

The objective test parameter measured is the time taken for a high-speed lap of a wet handling circuit. This is a broad ranging test that takes into account a number of tyre performance attributes, such as the tyre’s ability to transfer the car’s power to the road, and ultimately the amount of control the driver has. The subjective test goes beyond the lap time to give a greater insight into the tyre’s performance. The test driver applies a rating to a number of parameters, based on their knowledge and experience. They are focusing on driver experience – looking for safe, predictable handling, and effortless road performance.

LONGITUDINAL AQUAPLANING

Aquaplaning (or hydroplaning) is where water gets between the tyre surface and the road. Tyre tread should disperse water to prevent this.

The speed at which a tyre is deemed to be fully aquaplaning is when the front driven wheel speed is 15% faster than the speed the vehicle is actually travelling

The higher the speed achieved before full aquaplaning is reached, the better the tyre is at preventing the phenomenon. Davanti’s testing process creates the conditions for aquaplaning to engineer tread patterns that break up the surface of the water and drive it away from the contact area more effectively.

DRY STABILITY

Dry road condition stability should exceed all normal driving requirements.

On a demanding dry handling track, the tyre is rated on the following characteristics:

• Roll control
• Yaw stability
• Lateral grip
• Lateral stiffness
• Throttle lift-off
• Straight line stability

DRY STEERING

Dry road condition steering feel and response should exceed all normal driving requirements.

On a demanding dry handling track, the tyre is rated on the following characteristics:

• Driving effort
• On-centre feel
• Steering response
• Linearity

WET CIRCLE

Confidence when steering in wet conditions is integral to the performance of all Davanti tyres.

The vehicle is driven on a wet asphalt circle with constant steering angle applied, thus maintaining a consistent diameter.

The vehicle is accelerated up to a speed at which grip is lost, with the lap time at this speed measured by data logging equipment.

SAND TRACTION

Reliable traction on loose surfaces is a vital component of the performance characteristics of all-terrain tyres.

Sand traction is evaluated in two ways:

• Using a sand hill, the maximum achievable distance the vehicle can reach is measured.
• Using a sand hill, the minimum achievable time for the vehicle to reach the top is measured.

OFF-ROAD STABILITY

On loose surfaces, vehicle stability is essential. As the only part of the vehicle in contact with the ground, the tyre has a significant influence on the stability.

On a grass and mud off-road circuit, the tyre is rated on the following characteristics:

• Controllability at limit
• Power on/off cornering
• Transient stability
• Brake-in-turn
• Braking stability

OFF-ROAD STEERING

Confident and precise steering, with a pleasant feel, is of vital importance to all drivers of Davanti off-road.

On a grass and mud off-road circuit, the tyre is rated on the following characteristics:

• Feel/weight (on centre)
• Feel/weight (off centre)
• Response (on centre)
• Linearity

GRAVEL BRAKING

Possibly the most important feature of a tyre – the ability to come to a controlled halt in low-friction conditions.

On a hard-packed gravel surface, the brakes are applied and the distance covered whilst braking from 50 to 0 km/h is measured.

GRASS TRACTION

A common, but surprisingly tricky situation. Traction on the low-friction surface of wet grass, especially while towing, is essential for off-road tyres.

On a cut grass surface, the vehicle is driven from a standing start up to 40 km/h while towing a weighted trailer. Data logging equipment measures the distance the vehicle requires to accelerate from 0 to 40 km/h.

OFF-ROAD HANDLING

Conquering difficult terrain in a timely and comfortable manner – the mark of a great all-terrain tyre.

On a grass and mud off-road circuit, the fastest lap time achievable by the tyre is measured using data logging equipment.

MILEAGE

Driving performance – as important as it is – means little without the ability to maximise driving range and tyre lifespan mile after mile to deliver real value for money.

Tyres are tested on vehicles, driving on real roads.

A minimum of 20,000km is covered per set, and tread wear is measured at regular intervals to evaluate wear rates throughout the life of the tyre tread.