We recently celebrated the second anniversary of out car's ownership. I hope I take a good care of it, and we intent to keep the car for as long as possible.
I apply Krown rust proofing on annual basis.
I used to wash the underbody of the car with power washer. Sometimes (when it is cold) I power-wash the car with a soft power brush. I think it is quite safe for the finish because of the water/shampoo mixture that runs through it at a quite high rate.
During last two winters I washed the car every week, giving it the fresh wax job almost every time. My car has more cosmetics then my wife...
Anyway, this season I started to question my own practices and what seems to be the common sense for winter car care.
First, the car wash itself. Here in Southern Ontario the salt stays on the road from about mid- November till about April. It does not go away even when it is dry. The salt forms very fine dust that gets everywhere, and there's no way to avoid that.
What happens after a good car wash is that the wet surface happily absorbs all the dry salt it could get, voiding the benefits of the car wash. This is very true after any car wash (touchless, detail shop, whatever) that you have to drive elsewhere after.
Even if you wash the car in your driveway and put the car into (warmer) garage like I do, the salt gets to the underbody next morning, and in 10 minutes it is as covered as before the wash.
There's an interesting twist- when you wash the salty car when it is dry, for a brief period you introduce it to the nice brine, until it is washed away. So otherwise pretty neutral salt (given low air humidity) has a chance to get active, although briefly.
When it is wet outside, things are even nastier, there's no point in a car wash at all.
Second thing is going through touchless wash, return home and wax the car. I think it is the worst you can do. Besides all the "benefits" of the filtered brine soak, this type of wash does not do a good job of cleaning. Waxing the car after it means grinding its finish with the grime residue that is left after the touchless wash.
The third practice that I question is keeping brined car in attached garage. It almost never gets below freezing inside my garage, no matter how cold is the weather. The car has never slept outside.
I realize that the brine is active to about -30C, but its activity does depend on the temperature. It is obvious that the car would be way better off standing outside in the cold. It is unfortunate that I don't have the place to put some sort of shed. And to me the ability to drive right away without scraping ice from windows outweighs the drawbacks of intensified corrosion from keeping the car inside...
So, what do you guys think? Considering the roads to be covered with salt all winter, is it worth to wash at all? Why? Remember, the car gets covered with salt in no time…