Tag Archives: hard-packed snow

10 Milestones of Ivalo Proving Ground

Nokian Tyres’ 700-hectare proving ground in Ivalo, Finland, is in use from November to May. With state-of-the-art equipment, the different tests and the expert staff make sure that all the extreme situations in winter driving are thoroughly studied.

1. Grip on Ice
Tammijärvi Lake is the largest lake at the Ivalo proving ground. Three straight test tracks measuring one kilometer each are set upon its icy surface each winter in order to measure tyres’ grip during braking and acceleration. Three 20 meters x 1,000 meters ice straights

2. Grip on Snow
The friction values of a tyre’s lateral and longitudinal grip are measured using equipment installed in the test vehicle. Tests are conducted on two straights of different lengths. The surface on these tracks is made up of hard-packed snow. Test tracks: 20 meters x 1,000 meters and 25 meters x 500 meters.

3. Hill Test
The hill test is used to measure and evaluate how a tyre (in Swedish: däck) climbs up a steep slope. Three routes with different profiles and steepness and a different number of curves lead up to the hill. Test results are obtained from the test driver’s comments and objective measurements – maximum 20% incline – three routes: 1,000 meters, 900 meters and 500 meters.

4. Handling on Ice
Conducted on an icy surface, this handling test measures a tyre’s maximum grip in curves with different radiuses and on a long straightaway. Measurement results and the test driver’s views are used in the evaluation. Two ice-covered tracks: 800 meters and 1,000 meters.

5. Handling on a Snowy Track
In this handling test, an experienced test driver compares the tyres’ behavior on a snowy track, i.e. on a hard-packed snow surface. The route measuring just over 12 kilometers simulates ordinary road conditions with its slopes and curves.- a winding road with slopes and curves, about 12 kilometers long hard-packed snow surface

6. Handling on a Snowy Track II
The second track intended for evaluating tyres’ behavior in snow is about one kilometer long. In testing terms, this is a so-called index track where tyres’ basic properties can be defined. The demanding route features a large number of curves with different radiuses. Test drivers find out the difference between various tyres by driving at the extreme limits of the tyres’ grip and at extremely high speeds. Measured driving times and the test drivers’ subjective assessments complement each other.

7. Lateral Grip and Longitudinal Stability on Ice
A tyre’s lateral grip and longitudinal stability are determined by evaluating its behavior on ice. Lateral grip is tested on an icy circle track. Lap times are recorded in the circle track test, and otherwise comparisons are based on subjective views of the tyre’s handling. When carrying out tests on ice, testers aim to keep conditions as constant as possible by roughening the track’s surface with a specially designed roughener. The objective is to keep the ice evenly slippery. Circle diameter 300 meters – handling track 2,300 meters.

8. Maintenance Area: Office and Garages
The Ivalo proving ground has a maintenance building, housing the office premises and a meeting room. During the busiest periods, testing is carried out on an extremely tight schedule, with all available time utilized as efficiently as possible. The garages are used to store and service test cars and equipment used for repairing the test tracks, and to mount and change tyres.

9. Handling on Ice II
This handling test which is conducted on an icy surface measures a tyre’s maximum grip in curves with different radiuses and on a long straightaway. Tyes are evaluated based on measurements and test drivers’ views. Ice-covered track: 900 meters.