During the winter season, snowy or icy roads are generously salted and treated with melting products by municipal services. While these chemical mixtures are essential for road safety, they are the worst enemy of your vehicle's bodywork and chassis.
Why is winter washing crucial?
Salt combined with moisture creates an aggressive chemical reaction that significantly accelerates the oxidation and appearance of rust on metal components, brake lines, and rocker panels. Waiting until spring to clean your vehicle is a costly mistake.
How often should you wash it?
The general rule: It is recommended to wash your car in winter every 1 to 2 weeks (approximately every 10 to 15 days).
After each major storm: As soon as the roads have been salted and the conditions slightly improve, a wash is necessary.
According to usage: If you drive daily on highways or heavily treated secondary roads, a weekly wash is ideal.
Best practices for washing in winter
Opt for washes with the "rocker panel" option: This area accumulates the most salt and is where corrosion begins.
Wash during mild weather if possible: Choose a day when the temperature rises slightly above freezing to prevent the water from instantly freezing on doors or locks.
Apply a protective wax: Before the big freeze, a good coat of wax acts as a waterproof shield against salt and dirt.
Protect the seals: Thoroughly dry the door edges after washing and apply a silicone-based product to prevent the doors from sticking due to frost.
Sources used
Guide Auto - Maintenance and car washing tips during the winter season.
CAA-Quebec - Recommendations on protection against corrosion and road salt.