Road salt and winter wheels

What salt does by March

The city brines and salts the 417, the arterials, and the collectors. The mix stays wet around −10°C and packs into the barrel of the wheel. On an alloy, it creeps under clear coat at the spoke roots and around the centre bore. On the hub, it rusts the mating face so the wheel will not come off at the April changeover without a hammer.

A dedicated steel winter wheel takes that abuse on a cheap, paintable surface. The summer alloys stay in the garage. That split is the usual Kanata setup, and it pairs with a full set of winter tires that never has to be remounted if the tires live on those steels.

Care that is actually worth doing

• Rinse the inside of the wheels, not only the face, every few weeks. The barrel holds the salt.
• After a thaw drive, wash the underside of the car. Salt sits in the spring seats and on the brake shields.
• Before storage, clean the hub face and put a light coat of anti-seize on the hub centre, not on the lug threads, so the wheel comes off in spring.
• If a wheel is already bent from a spring pothole, replace or repair it before it goes back on. Salt will occupy the crack.

Clear-coat failure on an alloy is cosmetic until the corrosion reaches the bead seat. Once the bead seat pits, the tire loses air. That is the point where a winter alloy becomes more expensive than the steel wheel you did not buy.