What kind of salt is used on roads?
There are three different types of road salt (vacuum, rock and sea), which are typically one component of four different formulations of the stuff that’s put on the roads: sodium chloride, magnesium chloride, calcium chloride and potassium chloride. (You can read more about all of this here.)
Plus, in some areas, a salt brine is put down on the roads before the winter weather even hits: great for safety, but particularly bad for your car. If you want to learn more about the science of why salt is put on roads in the winter, read this article from Jalopnik.
What does salt do to cars?
For a brief overview of how road salt is likely harming your vehicle, we’re going to turn it over to Chris Jenak, a mechanic at Glastonbury Oil and Service in Connecticut, who recently spoke with News 8 on this very topic:
“Back in the day, when we used salt and sand, you had rust and you had corrosion, but it seems like within the past 10+ years, with this calcium chloride, everything is rotting out on vehicles…Rotted brake lines, rotted fuel lines…fuel pumps…some frames rotting out. Anything that has a metal composite to it, this chemical just gets on, and just eats and rots it, and corrodes away.”
This includes parts like the:
- Exhaust system
- Muffler
- Coil springs
- Subframe
- Hydraulic brake system
Now, back to Jenak for a breakdown on what this has to do with rust:
“It’s a combination of normal rusting of every vehicle because every car rusts. But this calcium chloride just basically puts the corrosion level and corrosion factor into overdrive. It’s a moisture activated chemical, so even when the winter is over, you get a nice, rainy day in the summer or a moist dewy day, it activates the chemical. It continues to sit there and react and eat away at all the metal.”
How to Prevent Your Windshield From Cracking This Winter
We’ve been all about windshields here lately—between this hack for defogging them, and these…
How to protect your car from salt damage
While different salt formulations may cause damage faster than others, these general tips from DMV.org are your best bet regardless of the type that’s used in your area:
- Wax your vehicle every year, right before winter weather begins.
- Get the salt off your car ASAP after driving through it. (Even if you’re someone who prefers to wash your car yourself, this is a good excuse for a trip to the car wash.)
- Don’t skip the undercarriage. Whether washing your car yourself or picking a car wash, make sure there’s a way to spray off the bottom/underneath part of the car.
- Consider pre-treating the undercarriage. This is something some auto body shops offer.
- Do a pre-winter check of the vehicle. Either slide under the car yourself (if you know what you’re doing) or have a professional do it. The aim is to spot any potential weak or rusting parts and take care of them before the winter road salt does.
- Stay away from puddles and plow trucks. This is good winter driving advice in general (you never know how deep that puddle is going to be), but also helpful in terms of salt. Puddles tend to have a lot of salt in them, and while it may seem safer, driving directly behind (or close to) a plow/salt truck positions your vehicle for maximum salt exposure