2021 Tire Reviews Winter Tire Test

For dry braking, I drive the test vehicle at an entry speed of 110 km/h and apply full braking effort to a standstill with ABS active on clean, dry asphalt. I typically use an 100–5 km/h measurement window. My standard programme is five runs per tire set where possible, although the sequence can extend to as many as fifteen runs if conditions and tire category justify it. I analyse the full set of runs and discard statistical outliers before averaging. Reference tires are run repeatedly throughout the session to correct for changing conditions.

For dry handling, I drive at the limit of adhesion around a dedicated handling circuit with ESC disabled where possible so I can assess the tire's natural balance, transient response, and limit behaviour without electronic intervention masking the result. I usually complete between two and five timed laps per tire set, depending on the circuit, tire type, and consistency of conditions. I exclude laps affected by clear driver error or obvious environmental inconsistency. Control runs are carried out frequently throughout the session, and I often use multiple sets of control tires so that wear on the references does not become a meaningful variable. For more track-focused products, I also do endurance testing, which is a set number of laps at race pace to determine tire wear patterns and heat resistance over longer driving.

For wet braking, I drive the test vehicle at an entry speed of 88 km/h and apply full braking effort to a standstill with ABS active on an asphalt surface with a controlled water film. I typically use an 80–5 km/h measurement window to isolate tire performance from variability in the initial brake application. My standard programme is eight runs per tire set where possible, although the sequence can extend to as many as fifteen runs if conditions and tire category justify it. I analyse the full set of runs and discard statistical outliers before averaging. To correct for changing conditions, I run reference tires repeatedly throughout the session — in wet testing, typically every three candidate test sets.

For wet handling, I drive at the limit of adhesion around a dedicated handling circuit. I generally use specialist wet circuits with kerb-watering systems designed to maintain a consistent surface condition. ESC is disabled where possible so I can assess the tire's natural balance, transient response, and limit behaviour without electronic intervention masking the result. I usually complete between two and five timed laps per tire set, depending on the circuit, tire type, and consistency of conditions. I exclude laps affected by clear driver error or obvious environmental inconsistency. Control runs are carried out frequently throughout the session, and I often use multiple sets of control tires so that wear on the references does not become a meaningful variable.

To measure straight-line aquaplaning resistance, I drive one side of the vehicle through a water trough of controlled depth, typically around 7 mm, while the opposite side remains on dry pavement. I enter at a fixed speed and then accelerate progressively. I define aquaplaning onset as the point at which the wheel travelling through the water exceeds a specified slip threshold relative to the dry-side reference wheel. I usually perform four runs per tire set and average the valid results.

For curved aquaplaning, I use a circular track, typically around 100 metres in diameter, with a flooded arc of controlled water depth, usually about 7 mm. The vehicle is instrumented with GPS telemetry and a tri-axial accelerometer. I drive through the flooded section at progressively increasing speed, typically in 5 km/h increments, and record the minimum sustained lateral acceleration at each step. The test continues until lateral acceleration collapses, indicating complete aquaplaning. The result is expressed as remaining lateral acceleration in m/s² as speed rises.

For snow braking, I drive the test vehicle at an entry speed of 50 km/h and apply full braking effort to a standstill with ABS active on a groomed, compacted snow surface, measuring 45-5 km/h. I generally use a wide VDA (vehicle dynamic area) and progressively move across the surface between runs so that no tire ever brakes on the same piece of snow twice. My standard programme is twelve runs per tire set, although the sequence can extend further if the data justify it. I analyse the full set of runs and discard statistical outliers before averaging. The surface is regularly groomed throughout the session. To correct for changing snow surface conditions, I run reference tires repeatedly — typically every two candidate test sets.

For snow traction, I accelerate the vehicle from rest on a groomed snow surface with traction control active and measure speed and time using GPS telemetry. I typically use a 5–35 km/h measurement window to reduce the influence of launch transients and powertrain irregularities. I use a wide VDA (vehicle dynamic area) and progressively move across the surface between runs so that no tire ever accelerates on the same piece of snow twice. The surface is regularly groomed throughout the session. I complete multiple runs per tire set and average the valid results. Reference tires are run typically every two candidate test sets to correct for changing snow surface conditions.

For snow handling, I drive at the limit of adhesion around a dedicated snow handling circuit with ESC disabled where possible. The circuit is groomed and prepared after every run while tires are being changed, so each set runs on a consistently prepared surface. I usually complete between two and five timed laps per tire set, excluding laps affected by clear driver error or obvious environmental inconsistency. Because snow surfaces degrade more rapidly than asphalt, control runs are carried out more frequently — typically every two candidate test sets.

For snow lateral grip testing, I use a circular snow track of fixed radius, broadly aligned with ISO 4138 principles. The surface is regularly groomed throughout the session. I progressively increase speed until the maximum sustainable cornering speed is reached. I normally record multiple laps in both clockwise and counterclockwise directions to reduce the influence of surface bias. Because snow surfaces degrade more rapidly, the control tire is retested at regular intervals and I often use multiple sets of control tires.

To assess comfort, I drive on a wide range of road surfaces (often dedicated comfort tracks at test facilities) at speeds from 50 to 120 km/h, including smooth motorway, coarse surfaces, expansion joints, broken pavement, and sharp-edged obstacles. I evaluate primary ride quality, secondary ride quality, impact harshness, seat-transmitted vibration, and the tire's ability to absorb sharp inputs. Ratings are assigned on a 1–10 scale relative to the reference tire.

I measure external pass-by noise in accordance with UNECE Regulation 117 and ISO 13325 using the coast-by method on a compliant test surface. Calibrated microphones are positioned beside the test lane, and the vehicle coasts through the measurement zone under controlled conditions. I record the maximum A-weighted sound pressure level in dB(A), complete multiple runs over the relevant speed range, and normalise the result to the reference speed required by the procedure.

Rolling resistance is measured under controlled laboratory conditions in accordance with ISO 28580 and UNECE Regulation 117 Annex 6. The tire is mounted on a test wheel and loaded against a large-diameter steel drum. After thermal stabilisation at the prescribed test speed, rolling resistance force is measured at the spindle and corrected according to the relevant procedure. The result is expressed as rolling resistance coefficient, typically in kg/tonne.