Leave car outside when below freezing? - PeachParts Mercedes-Benz Forum

domchang · #1 10-31-2003, 09:28 AM

Was hoping to get advice/opinions from guys who drive their MBs in snowy and freezing weather.

We use stuff called magnesium chloride here in the Denver Metro area when it gets snowy/icy. Here's what I was thinking of doing with my 1987 420SEL which I am planning to use (first winter ever that I've owned it) as my snowy/icy days driving car:

If the temp is below freezing or near it, and I've been driving in the stuff, leave the car outside so the stuff stays frozen on the underbody of the car. Once the temps go above freezing then take her to the car wash and hose off the magnesium chloride asap to prevent rusting and such.

Or...

would it be better to drive her into my garage after driving in the snow/ice and knowing it's got magnesium chloride on the underbody and let the snow/ice melt off in the garage...then when the weather is above freezing, hose her off as above at the local car wash?

opinions? experience with either method?

thanks in advance

dchang

blackmercedes · #2 10-31-2003, 09:45 AM

From the Frozen North: (It's -16 here this morning...)

Most of us that want to keep our cars in decent shape don't use heated garages. The problem is condensation. The freezing/thawing cycle is really hard on your car. Condensation can get into the fuel system, braking system, etc. It is very hard on the exterior surfaces as you have figured out. The thawing allows salt and other melting agents to become liquid on your car, and they are much more active in that state.

I keep my car in the garage, unheated. It keeps the snow and frost off. Then, on cold nights, I use the block heater to take the strain off the engine. I also use synthetic oil as it has a much lower pur point and flows much quicker in the cold. At least once a week it goes to the car wash.

Kestas · #3 10-31-2003, 09:59 AM

There was an article on this in Automotive Engineering about 20 years ago. This article only addressed the rust issue. Corrosion is active when the car is wet... less active when frozen. The WORST thing for a car during winter is a heated garage. The best thing is to keep it outside, preferably under a car port that blocks the wind and precipitation.

Since there is a trade off between corrosion and startability, I'd favor worrying about corrosion. I don't think the increased engine wear during cold starts is all that significant compared with body corrosion. Usually a Benz is scrapped when the body has given up. Engines can be more easily repaired than body corrosion. Or at least the issue of startability can be more easily controlled by proper oil management.