Piston Slap: Fight Rust With Mother Nature?

Karl writes:

Sajeev, I am not sure if this has been covered before, but I am writing about washing cars in winter. I finally have a car that is new enough and nice to worry about keeping the body in good shape for a long time. It will not be driven that regularly, so I expect to keep it for a decade–I tend to keep my cars a long time. I remember reading long ago (okay, long, long ago) about not washing vehicles in freezing weather. Well, I live in Wisconsin, so that is a third of the year. I want my new purchase to last, so what should I do to preserve the paint and the body?

Sajeev answers:

I’ve spent most of my life in the Texas Gulf Coast, so I shouldn’t answer this question. But with the (thankless) hours spent as an automotive forum moderator, I shall. There’s always a thread on preserving sheetmetal in the Rust Belt: I’ll share what I’ve heard from intelligent forum contributors.

I recommend washing a car in the winter, especially if it’s done weekly and using a proper underbody wash to keep road salt off your ride. I’d also polish the car with a polymer-based wax to protect the paint the entire season. Then grab some mudflaps and get ready for the big chill.

Most importantly, don’t let the car thaw in a heated garage every day. The logic says that a car with salty ice in every orifice protects itself better than one that turns into salt water every evening, permeating into every poorly protected sheetmetal crease. I’ve heard (keyword: heard) of cars that live completely rust free with a strict regiment of living outside during winter, with a heavy coat of “water” from the owner so it can completely seal the drainage gutters and door seams as it freezes.

Makes sense: I’d soak every non-moving part in water and let Mother Nature protect my ride from the government’s evil, evil salt fixation. Which is definitely easier on the environment than the toxic chemicals in automotive undercoating. And that’s far cheaper too.

(Send your queries to mehta@ttac.com)