Winter 2010 was cold and snowy in England; and the Saab required some new tyres. A set of four Vredestien mud and snow155 x R15 tyres were purchased, to assess their road holding in these winter conditions and throughout the following year.
The Vredestien tyres carry both the M+S (Mud and Snow) marking and the snowflake pictograph.
The M+S text indicates that the tread pattern is designed to work with mud and snow. It has a more open pattern to allow the tyre remain clear in use, with bocks of tread and no circumferential grooves.
The tyres also had holes to accept the installation of metal studs.
The snowflake symbol indicated that the tyre met an American standard and was made from softer rubber than normal 'summer' tyres. This different compound was confirmed by checking the two tyre types with a Shore standard gauge.
The summer tyre read 75 shoreA
The Winter tyre was 62 shoreA
A softer compound by16%.
Road Test.
Straight from the garage in the cold of the morning it was clear the Vredestien tyres gave more traction than the old summer tyres - although these were arguably worn summer tyres.
Grip in the snowy slush, compacted ice and fresh snow were all noticeably improved, and driving, braking and cornering maneuvers could be approached with more confidence.
The following day the car was taken for a longer drive into the country, documented in the video below.
Winter driving on the new tyres
Snow tyres are a compromise and summer performance was therefore expected to be less good than the previous Firestone's. Ideally they would be fitted on some separate wheels and swapped out when temperatures were warmer, but I lacked the space and funds for this, so they would be used all year round.
The most noticeable downside was a reduction in directional stability, most obvious at high speeds and in cross winds. This was expected, due to the lack of circumferential grooves on the winter tyres. This was accompanied by a slight vagueness in the steering, nothing too bad but the smallest changes in steering adjustment were now not translated into direction changes of the car. This was improved by lifting the tyre pressures to 30psi but was still present.
There was also a higher susceptibility for the car to understeer on wet roads. Saabs (like all safe cars) have always been designed to understeer when grip is inadequate, but this would now occur at lower speeds when powering through a corner.
On the positives - braking was as good as ever and driving on dry roads was very sure-footed and reassuring. Wear rate didn't seem to be a problem either.
However it was at lower temperatures and in snow and ice that they really excelled.
Mobirise