Rust belt. Frequent car washes vs underbody coating.

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Apr 23, 2024
Threads
4
Messages
72
Location
Chicago, IL
Just bought a new to me 2017 LX570. This is the nicest and most expensive car I've ever owned and I want to keep it until the wheels fall off. My 2008 4Runner has almost 300,000 miles and it's very rusty from all the salt that Chicago and IDOT throw on the ground. Would frequent car washes with undercarriage spray be just as effective as fluid film or another protective coating? Or should I just bite the bullet and coat the undercarriage to prevent the rust cancer from devouring my nice car?
 
If you mean automatic car washes then it's not a good idea, I heard the water is re-cycled, you can't guarantee that -- you are spraying more salinity infused water onto the car.

If the weather is above freezing point or you have a heated garage, you can do the film and do some gentle rinsing at home yourself
 
Frequent washing is better than nothing, but an annual application of something like Fluid Film is much better. Where you live you can’t wash the salt off often enough to prevent rust. Don’t use hard under coatings. There is member on here in the Chicago area who has applied fluid film to 200s. @GoISU.
 
I had Woolwax done underneath my LC about two years ago and I go to automatic touchless washes once a month. There's no issue with rust and the yearly touch ups I get for the coating is very very minimal.
 
I live in upstate NY I take my vehicles to the self service bay blow all the s*** off from underneath once a week in the winter time. This has worked for all my vehicles and they all do not have any rust issues. As stated above use fluid film, do preventative maintenance and you should be good.
 
I’ve used Fluid Film and other lanolin products on my vehicles once a year for the last couple of decades and they stay rust free. As some have stated, it may wash off after very repeated driving in rain but once a year touch up will do. The more road grime imbedded in the fluid film layer the better as it helps it from being washed off.

I spray inside all of the doors, fenders, rocker panels, tailgate, inside every frame hole, etc. Even my FJ60 is rust free. YouTube has lots of great videos on how to do it yourself or just take it somewhere.

Never use the hard coatings as they will trap moisture and make your car rust even faster.
 
Fluid film each November. Apply a dab of marine grease to the head of each KDSS screw at the same time. It ain’t 100% stop the rust but it will really really slow it down. I’ve had my truck in Chicago for 8 winters now and although it’s a dirty oily mess to work on if you wipe the factory surfaces they’re almost rust free.

The body itself should hold up pretty well. I hit the manual car wash and I wash and wax it just using the wand about once a month in the winter to get the crust off. Touch up any paint chips with paint AND clear coat

What does rust for me are the aftermarket stuff (steel bumpers and steel sliders once the power coat is broken, and any basic zinc coated nuts and bolts holding them on). FF helps but only so much in those cases.
 

Users who are viewing this thread

Back
Top Bottom