Experts Say To Wait For This Temperature Before Washing Your Car

Okay, let's see a quick show-of-hands from everyone who's made the mistake of brushing up against the side of your vehicle and ended up with a big smear of salt and road grime on your nice winter coat. My hand is up, and I'm sure that most, if not all of you have had the same thing happen.

If your car is currently the color “winter gray-brown” instead of whatever you paid for at the dealership, you’re not alone.

Between road salt, slush, grime, and whatever mystery substance splashes up from the highways and city street gutters, vehicles in Northern Illinois and throughout the Midwest take an absolute beating this time of year. The desire and temptation to wash your ride is real. The fear of turning it into a frozen popsicle? Also very real.

Let's see what the experts have to say about car washing in the middle of winter.

According To Those In The Know, Vehicle Washing During The Winter Is All About A Magic Number

That magic number is apparently 40 degrees.

That temperature gives you enough breathing room to wash your vehicle without worrying about door seals freezing shut, locks icing over, or water turning into decorative glaciers in your wheel wells. Some say you can technically wash a car at 32 degrees, but that’s less “recommended” and more “Sure, give it a try and see what happens. You might be okay.”

If you absolutely can’t wait and the forecast isn’t cooperating, there are ways to minimize the risk. Touchless car washes are your safest bet in winter, since they rely on high-pressure water and heated air instead of brushes that can trap moisture. Better yet, many use warm water, which helps rinse away salt without immediately refreezing.

If You're Going To Do It, Here's Where To Focus On Your Vehicle

The undercarriage is where salt does its dirtiest work, quietly eating away at metal while you’re minding your own business. Even a quick rinse underneath can make a big difference, and many experts argue it’s more important than making the hood sparkle in January, February, and March.

So, what would happen if you just had to wash your vehicle today, and didn't care that the daytime high temperature is only going to reach 15 degrees and the overnight low will be zero?

Here's What Happens With A Carwash At 15 Degrees

• First, the water wouldn’t even wait for you to leave the car wash. It would start freezing almost instantly on the paint, in the mirrors, inside door seams, and especially in the wheel wells. You’d drive away trailing tiny ice shards like a low-budget Frozen sequel.
• There’s a very real chance your doors would freeze shut. Same with the gas cap. Power locks can ice up internally, leaving you standing in a parking lot hitting the key fob like it personally betrayed you.
• Any moisture left behind becomes a solid sheet of ice. Side mirrors freeze mid-adjustment. Windows might refuse to roll down. If water gets inside the window seals, you could hear some truly unsettling cracking sounds later.
• Water can freeze around brake components. Best case would be loud scraping noises. Worst case would be temporarily frozen brakes that feel stuck when you first try to move.

The bottom line is that washing your car today wouldn’t make it cleaner, it would just turn it into a salt-free, ice-covered monument to your poor life choices. The salt might be gone, but now you’ve got a rolling glacier with frozen doors and regret.

At 15 degrees, the filth is probably doing your car a favor by acting like a temporary protective layer. Wait for a 40-degree day, or at least a day that doesn’t require a parka.