From the first plow run in November until the street sweepers come out in spring, salt brine coats the lower half of every car in London. The paint you can see is rarely the problem. The damage starts underneath, on brake lines, the subframe and the inside lips of the wheel arches.
You will not win the salt fight in February, and you do not need to. The goal is to stop salt from sitting on bare metal for weeks at a time, especially through freeze and thaw swings, when meltwater carries it into seams and then dries it back into a crust.
Crouch down and look behind each wheel, along the rocker panels under the doors, and at the back of the rear bumper. Those are the spots where slush packs in and stays wet. If you see white tide lines there, the underside looks worse.
While the roads are white, aim for a wash every seven to fourteen days, and always within a few days after a big storm once the plows have finished. Commuting on the 401 or 402 throws more brine than city streets, so highway drivers should lean toward weekly.
Watch the forecast for a day at or above freezing and wash in the early afternoon, when it is warmest. Water drains out of seams and door bottoms before it can freeze, and you get time for the car to dry on the drive home.
After the bay signal says you are done, pull into the parking area out front and run a dry cloth around each door seal, the bottom edge of the doors and the trunk or hatch seal. Open and close each door once. It takes two minutes and saves you from a door frozen shut the next morning.
If big chunks of ice are hanging in the wheel wells, knock them loose with your boot before you drive in. Water will not cut through a frozen block, and the spray will reach the metal behind it much better once it is gone.
Once the salt trucks stop for the year, usually in March or April, give the car one thorough wash that includes the underside. Salt left in place through a warm, damp spring does more harm than salt in January.
Salt damage is an underside problem, so the under-car spray in Full Wash is the part that matters most in winter. Quick Wash cleans the body but skips underneath, which makes it fine for a mid-week freshen-up on a car you rinsed properly a few days earlier. Step up to Luxury for the end-of-season wash if you want the rust inhibitor applied after the salt comes off.
Quick plus an under-car spray. The one for salted roads.
$2 more than Quick Wash
Yes, the wash itself is fine. The trouble comes afterwards, when water left in door seals, locks and the gaps around the trunk freezes. Wipe the seals, open each door once, and if it is very cold, use your heated mirrors and run the defrost on the way home.
Full Wash and Luxury Wash both include an under-car spray. Quick Wash does not, so it cleans the body and glass but leaves the underside as it was.
Wait until the plows and salt trucks have finished and the roads have dried a little. Washing while fresh brine is still being thrown around just means you drive home and coat the car again.
Yes. Rinsing salt off slows down rust that has already started, and it keeps it from spreading into brake and fuel lines nearby. A body shop can tell you whether a spot needs treatment.
