Liquid Brine and Liquid Magnesium Chloride are great to treat the roads in winter time but it is also very destructive to the autos we drive. Road treatment types Local mechanic talks about salt brine and what it could do to your car Parts of your car, however, at risk from rust and corrosion from salt include: - Exhaust system - Muffler - Coil springs - Subframe - Hydraulic break system - Paint on doors, bumpers, and fenders DMV.org recommends waxing your car before winter weather should strike. You should also avoid puddles and plow trucks. Puddles hold larger amounts of salt, and driving behind the plow means you will be the first to drive through a fresh layer of salt. You can pretreat your vehicle’s undercarriage as well. Collision shops offer an oil solution pre-treatment that can be sprayed on your vehicle’s exposed parts. This coating will help prevent salt and water from the road sticking to metal parts of your vehicle. DMV.org recommends washing your car after a snow storm as quickly as possible, and make sure you go through a drive-through car wash that has undercarriage clean. Why is Brine Bad for Your Car? What makes brine so desirable as an ice fighting road treatment also makes it harder on your car. Brine not only stays in places on roads, but when kicked up by driving over pavement treated with it, it stays on the underside of your car too. Crystals of salt bounce of roads, and they also bounce off your car. But brine coats every nook and cranny on your vehicle's underbody with two things that cause iron and steel to rust: water and salt. Either water or salt on their own are capable of causing rust of course, but the two combined are much more corrosive. Brine Also Often Contains Magnesium Chloride It is not just the fact that brine sticks well that makes it a good ice melter however. In many cases, brine is made with magnesium chloride. Magnesium chloride is a salt like the more familiar sodium chloride crystals, or rock salt, but it melts ice at lower temperatures. Unfortunately, if rock salt is bad for your car, then magnesium chloride is worse. Any salt is bad news for the iron and steel in your car when it mixes with water. That crust of salt your car develops in winter is just waiting to mix with water and eat away the steel. Fortunately, sodium chloride requires fairly high humidity levels to wick moisture from the air. In the cold dry air of winter, there isn't enough water in the air for the sodium chloride crystals to dissolve in. So they stay crystals and do relatively less harm to your vehicle. Magnesium chloride however mixes with water readily at low levels of humidity. Even in a dry time of year like winter, your vehicle's crust of magnesium chloride is busy sucking moisture out of the air and combining with it to form the water/salt combination that is so corrosive. And because it was spread as a brine to begin with, there is more of it, in more tight places on and under your car.