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Ask CATS 9: Put your car on a low-salt diet this winter.

Guest Contributor January 09, 2017
Close up of snow on car tires.
Our Consumer and Technical Services (CATS) team receives questions about car care, buying a new or used vehicle, auto repairs, vehicle inspection, driving costs and more. If you have a question for CATS, call 1-866-464-6448 or email us at cats@caasco.ca

Ask CATS #9: Put your car on a low-salt diet this winter. 

Driving is a challenge on slick snowy roads. Fortunately, de-icing and anti-icing chemicals applied to the roadway help improve traction and speed snow removal. Studies show that treating roads with these materials helps reduce crashes and saves lives. Unfortunately, some of the newer solutions used to melt ice and snow can also increase vehicle corrosion, particularly on older car models.

Today, rock salt is sometimes replaced with de-icing and anti-icing solutions that contain chemicals such as calcium chloride and magnesium chloride that are more effective in keeping roads clear. These new chemicals are applied as liquids, which are then thrown up by tires in a fine mist that sticks to the car body and undercarriage, and can penetrate into cracks and crevices where rock salt particles could not causing vehicle corrosion.

Sometimes the new de-icing and anti-icing chemicals are hygroscopic – they attract moisture and are often used as desiccants. This means that even after a vehicle is dry, deposits that contain these materials will pull moisture out of the air and contribute to ongoing corrosion.

Here are some practical maintenance tips to help you protect your car from salt corrosion:

  1. Wash your car. Regular car washes, including the undercarriage, are critical. Salt deposits left over from the winter will continue to corrode year-round. Even powerful pressure washers can leave behind corrosive deposits, and too much pressure may actually drive chemicals further into vehicle cracks and crevices. So washing your car with low pH detergents can help break up and neutralize corrosive deposits. Many automatic car washes now offer low pH pre-rinse cycles.

  2. Visit the body shop. Body scratches and chips should be repaired in a timely manner to prevent rust and corrosion, and regular vehicle waxing adds an effective layer of protection. Professional rustproofing, including asphalt undercoating and oil/wax body cavity sprays, may be helpful.

  3. Maintain your vehicle. Routine vehicle maintenance checks should include inspections of safety-related undercar components such as brake and fuel lines, whose failure could result in a crash or fire. Modern cars are far more corrosion resistant than earlier models, but for maximum vehicle life there is no substitute for proper car care.

In the next few months, make sure to check out our new Ask CATS video series, where we sit with the car pros and get the answers to all your automotive questions.

Got a question for CATS? Call us at 1-866-464-6448 or email us at cats@caasco.ca