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Should I wash the car during the winter?

I recently moved to Massachusetts and this is my first winter where I’m constantly driving on salty roads. My question is whether or not I need to wash my car, specifically the underside, on a regular basis.

I have heard from some people that I should do it on an almost weekly basis to prevent salt build-up. Others say not to bother because either the car wash is going to be recycling salty water, and/or the salt is just going to be back in a matter of minutes and I’ll have wasted $10.

Any suggestions? Is it worth it to keep washing every week, or should I just wait for spring?


Yes, you should go to a car wash regularly if you are driving in a “high salt area”. If the underbody wash is not part of the standard package, you should opt for the underbody wash.

We wash our cars in Maine all Winter long. I waited until the temperature got up to 35 degrees today. You will have lots of good wash days in Ma.

Absolutely. A couple years of no winter washing and there won’t be much of the car left.

Well as long as the salt is still on the roads, or will be back in in 24 hours, Washing will do little if any good. It might even do bad.

As long as the temperatures are well below freezing the best thing you can do is to leave the car out of the garage and let it stay frozen.  As long as all that gunk is frozen, it is not hurting anything.  I believe it was [i] Consumer's Reports [/i] that did a study on this and found more rust on those cars that people tried to wash and/or were parked in an attached garage (warmer than a non-detached garage) and found more ruse on the cars that were washed or stored where it was warmer. 

One problem with washing is, at least in some areas and at one time (I have not seen any information on this in over 10 years) car washes recycle water, so you are washing your car with water that contains salt (even if it is only the salt that was on your car to start with) and it is being forced into those hidden spaces where it may stay and not get washed out for a long time.

 Modern cars are far far more rust resistant than they use to be.  The metals used, the locations of drains and the materials applied have done great things to reduce rust damage. 

 One undisputed fact is your car will look better coming out of the car wash than going in.  

 For me, I only wash my car in the winter when the forecast is for a long period without snow and the salt has already washed off the road.

 However once it starts to melt, then is when the salt can cause damage.

One thing to keep in mind at automatic and spray car washes. A good portion of the water is recovered(drains) and then settled/filtered to remove sediment and then blended with fresh water back at sprayers. So when you wash in the winter you are spraying your car with water with a salt content.

I would not worry much on underside. Modern cars have excellent rust proofing. Just get the cheapest car wash and it will clean the bulk of gunk off. Nothing worse than touching a salt caked car(mine currently).

Washing the car in the winter using a hand wand is a good thing. It prevents buildup which can retain moisture. That thick salty brine you see on cars should be removed.

And, most important, it keeps the windows clear for good visability. It’s a true accident prevention act.

Taking it through an automatic car wash, especially one that sprays the underside, can be a bad thing. In addition to the typical wash brushes beating up the cars exterior, the high pressure sprays can force that recycled water into cavities it would not normally enter, ones that don’t vent well, and that can accelerate rust.

Hand wand. That’s my recommendation.

I used to wash-n-wax my cars ALL the time. I spent many many hours doing it.

Then one day, 21 years ago, my wife was inside taking care of our 3-month old daughter who had been up crying for a string of several nights (both were low on sleep). I was outside happily washing our cars. You can imagine the “discussion” that ensued.

That was the last time I ever waxed a car. I think I’ve washed them only 10 times in all those years. It was one of those cases where my wife woke me up to realize there are other important things to do in life.

I’m not saying don’t wash your car. It’s just there’s no need to be as excessive about it as I was.