For a seasonal tyre change the complete wheels (tyre on rim) are removed axle by axle and the stored wheels of the other season are fitted. In the process the garage checks tread depth, tyre age and condition, checks the tyre pressure and tightens the wheel bolts to the specified torque. On modern cars the tyre pressure monitoring system (TPMS) is also re-taught.
This is different from fitting new tyres: here the old tyre is pulled off the rim, the new one mounted and the wheel then balanced so it does not vibrate at speed. New tyres are due when the tread depth becomes too low – Switzerland legally requires at least 1.6 mm, while experts recommend at least 4 mm for winter tyres. A tyre age of over 6 to 8 years also calls for replacement, because the rubber hardens.
Switzerland has no general winter tyre obligation, but anyone who obstructs traffic or causes an accident with unsuitable tyres is liable and risks fines as well as cuts to insurance benefits. Winter tyres (or all-season tyres with the snowflake symbol) offer much more grip in cold, wet and snowy conditions. Many garages offer tyre storage so you do not have to keep the second set at home.
As a guideline (no guarantee): the seasonal swap of complete wheels costs roughly CHF 40–90, with balancing often included. Fitting new tyres including mounting and balancing is about CHF 25–45 per wheel, and tyre storage around CHF 60–120 per season. A new set of tyres itself costs a multiple of that on top, depending on size and brand.