Good Question: How Bad Is Road Salt For Your Car?

By Jason DeRusha, WCCO-TV

BROOKLYN PARK, Minn. (WCCO) — It is the winter hitch-hiker, none of us wants on our cars: Road salt. But how much damage does salt really do? And how often should we get our car washed?

“I believe, the more you can wash the car, the more you can keep some of that salt off, it’s going to benefit it in the long run,” said Matt Feehan, President of American Auto Body in Brooklyn Park.

And long-run is the key. Salt doesn’t generally show up as rust in short order. It takes time, and salt doesn’t cause rust in paint, it rusts metal.

“It has to go through the coating, through the e-coating, the primer, and into the bare metal to have an effect,” said Feehan.

So it’s not easy for salt to cause damage, especially considering the dramatic improvements in paints and primers.

“The corrosion-resistant coatings are better and the manufacturers are more complete in the painting processes,” explained Feehan. “All of these components are heavily built, so it’s largely a cosmetic issue.”

However, according to Feehan, salt can cause rust to build up on hidden parts of your car, and slowly eat away at the metal. It can take years for the rust to manifest itself on the car’s exterior.

Frequent washing gets to those hidden spots, according to Feehan, who washes his car once a week.

“It’s that middle temperature that’s from 5 degrees to 35 degrees that really makes a mess. If you know we’re going to go into a deep arctic plunge, so to speak, at that point get your car washed before that,” he suggested.

If you park your car in a warm garage and the ice on it melts, you are at higher risk that salt is going to damage your car. Rust forms when moisture and oxygen combine on metal, and salt accelerates that process because it corrodes.

“The idea of a car coming in and out of a warm environment is great for the driver, it’s great on motor and transmission, however on the body it is more difficult,” said Feehan.

He suggests waxing your car in the fall, which provides a layer of protection, making it easier to remove the salt, which inevitably will build up on your car in the Minnesota winter.

Read the “Gordy’s Garage” blog for more car tips.

WCCO-TV’s Jason DeRusha Reports

More from Jason DeRusha
  • Andrew

    I think this guy owns a car wash – the second you get your car washed, the car gets re-coated with salt as you drive away. I wash my car in the winter if the roads are dry – any other time, it’s a waste of money.


      I agree. I rather leave my car dirty in the cold because low temp slows the reaction of corrosion.

  • SgtUSMarine

    Bring back studded snow tires & use less salt.

  • K.

    The problem with studded snow tires was that they really tore up the roads. If you think the pothole problem is bad now, just imagine how much worse (and expensive) it would be if we brought back studded snow tires?

  • Mike

    After it gets so cold out the salt doesn’t work anymore. As far as studded snow tires goes, look at north dakota. Most of the roads out there are in better shape than the roads here in mn.. Not to mention the cars last a LOT longer due to no salt.

  • Tips for Your Car During Winter

    […] do not park your car in the heated garage and allow the salted ice to melt, as this can accelerate rust and other […]

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