Parking on grass

Is it true that parking on the grass will rust away the body of the vehicle? Only a portion of my vehicle is over the grass and it is moved every day.

First time I’ve heard that one. I park on grass for 10 hours a day five days a week because the area is shaded and keeps my car out of the sun. Rust is caused by salt on winter roads in northern states or by salt air if you live on a seacoast.

The only way I’m aware of that grass or weeds will cause body rust is in the case of cars that are parked for extended periods and the grass is allowed to grow deep and becomes wet from rain or dew.

On mowed grass and a vehicle that is used every day, never seen or heard of a case of rust caused by that.


This is a bit of conventional wisdom left over from a previous generation. It was probably true. Hard to tell; abandoned cars outdoors tended to rust away no matter what their parked surface happened to be.

For a modern car used daily I would disregard the warning as myth. Long-term storage is best accomplished indoors, of course.

No, there’s no truth to this. Park the car anywhere you choose and don’t worry. I’ve been parking my vehicles on grass for more than 20 years with no problems.

[b]This is true if a vehicle parked over grass for an extended period of time.

As the ground moisture evaporates under the vehicle, this moisture starts to corrode various components under the vehicle.

This is why it’s a good idea to put down some sort of vapor barrier on the grass where the vehicle will be parked for an extended period of time. Unfortunately doing this kills the grass.


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This is absolutely true. Parking on grass, dirt or gravel for extended periods will rust out your car much faster than parking on pavement, unless the ground happens to be very dry.

I have never seen any data, but I am content to believe that parking on grass every night will cause more moisture to accumulate on the under side of the car if there is not significant wind. This could easily cause more corrosion.

I will be more worried about fire. If the grass is tall and hits the hot muffler then it might catch fire.

Rust is caused by salt on winter roads in northern states or by salt air if you live on a seacoast.

WHAT?!? Rust is caused by three things coming in contact; iron (steel), water and oxygen. Salt only accelerates the process.

Here is the better reason why you should be very cautious about parking on grass, especially in very dry weather! Your catalytic converter.

If a sheet of plywood is left on the ground all day in my area it will be damp when flipped over. But I would imagine that if a car is driven every day and parked on a well manicured lawn there wouldn’t be much of a problem.