Car wash - any statistical benefit in rust prevention?

[Hemlock140]

I have some experience with this. I bought a used S-10 Blazer, and at the time had not checked it on Carfax which was pretty new then. It was great, ran fine, but eventually after a couple of years it died and turned out to not be getting gas. I remember it well because while waiting for the tow truck I was on the radio "a black SUV is blocking the right lane of the Redmond exit from 520."

With the fuel pump in the tank, the mechanic had to drop it. He called me and asked me to go down to the shop. The area under the floor and above the tank was totally rusted, and he had to replace the hard lines and sending unit along with the fuel pump.
I had him sand what was left of the underside of the floor and treat it with Por-15 before putting it back together. Then when I did check I found that it had originally come from New Hampshire. There was absolutely no other sign of rust under it, so the previous owners must have washed under it regularly, but just didn't get to that one hidden location. Soon after that I traded it in.

[Coldjensens]

I often wonder about this too. By the time you get home, the vehicle is covered in salt again. Did it do any good?


I wash my truck in the spring to get salt off. Usually wash it a few times. I wash it again whenever I go off-road and it gets really muddy.



I do not have rust issues, my last truck had a little but when I sold it everyone who looked at it commented on how little rust it had for a 15 year old truck. It had a little, but hard to notice.



I have friends who religiously wash their car or truck every weekend. They also have no rust on their car or truck, but they do not keep them long enough to really know whether it makes any difference. The kind of people who wash their vehicle constantly do not seem to be the kind of people who keep their vehicle for more than 5 or maybe 7 years, so there is no way to really know.

[BostonMike7]

My car is going on 10 years old. Ever since new, i've washed it at a local auto car wash about once per month. Gets driven in the snow and salt. After a big storm, when the roads dry off, i typically wash it, so maybe 2x per month in the winter.

I'll probably hand wash it once in the spring to get all the salt out of the door jambs and trunk jambs and such, but that's about the extent of it.

No body rust, but the rust i would care more about is the underside. I've been doing some suspension repairs lately. 10 years, 160K miles driven in salt/snow. I've found the fasteners do not have any issue coming off. I'm able to do it without the use of impact tools. I've worked on some rusty cars in the past and have had nuts rusted to the point there is nothing to grab with a wrench.

The only rust on the underside of the car, was the flex pipe which broke last summer. $30 and 20 mins with my welder and that was fixed.

Paint does have some swirls, but this is now a 10-year old car with 160K miles. I don't care anymore. What is great though is how well bolts and such release when i'm trying to do things like change a control arm due to bad bushings and such. I love that

Is that because of the carwashing? Or do manufacturers use better anti-rust coatings and such on hardware and such? I couldn't tell you.

[2011KTM530]

I just wish road maintenance would go back to just plow and sanding. Salt is bad for the environment, watersheds and vehicles. Or just use beet juice or some other non salt substitute.

[tommy64]

Most serious rust forms under the car. The frame rails, any bare steel fasteners such as bolts/clips etc, and around wheel openings.

Taking your car each spring to a car wash, putting it up on jackstands with the wheels off and getting underneath for an hour or so to blast water into these areas can help a lot.

But washing the exterior paint isn't gonna do much.