How to Prevent Road Salt From Rusting a Car

by Josh Baum

Few substances are as corrosive and harmful to car parts than highway melting salt. Whenever you drive in areas that have received winter precipitation, you pick up particles of this salt and take it with you. Then, as it warms up, it goes to work spreading rust and eating away at your car. If you live in an area with icy winters, you can't avoid this problem completely, but by following the steps outlined below, you can do your best to keep the salt from corroding your car.

Try your best to limit driving during and immediately following a snow or ice storm. Salt trucks usually start spreading salt a few hours before an anticipated storm, and they often continue the process until a few hours after the storm has ended. This period is when your car is likely to pick up the most salt, so prevention is one of your best means of keeping your car clean.

Avoid storing your car in heated spaces. At freezing temperatures, highway salt can't do much to hurt your car; it has to warm up to start contributing to rust. If you pick up salt during the day and keep your car in a heated garage at night, you will accelerate the corrosive power of the salt at an amazing rate.

Take advantage of warm spells throughout the winter season by washing the undercarriage of your car every time the temperatures rise above freezing. Salt doesn't get spread during these warm periods, so if you can wash it all away at your local car wash, you can start with a clean slate. Just be sure to get this done during the peak temperatures of the day so that your undercarriage (and possibly your car doors) don't get frozen overnight.

Wash the undercarriage thoroughly as soon as the temperatures start rising in the spring. As stated above, heat is the activating agent for the corrosive powers of salt. If you can get it all cleaned up before the first warm day, you stand a good chance of avoiding any serious rusting from the winter season.


  • check Not all car washes offer undercarriage washes, so shop carefully. Some car washes allow you to wash only the undercarriage of your car. This is often an economical option for drivers who want to protect their cars from salt but who don't mind driving a dingy car all winter.

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