Road Film - If you drive your car in the rain your car has road film

[Mike PhillipsMike Phillips is verified member.]

Road Film - If you drive your car in the rain your car has road film



Road Film

Road film is the oily film splattered all over your car when you drive in the rain.

Road Film also called Traffic Film tends to accumulate most visibly on the back of a vehicle and also the lower portions of a car but the truth is, if you drive your car in the rain, it's everywhere.

Over time, road film impacts ONTO the paint to the point where a normal car wash will not remove it. The best way to remove it is to use a mechanical means via one of these options,

1. Paint Cleaner
2. AIO or All-in-One cleaner/wax type product
3. Compound
4. Polish

Driving in the rain - For most of us it's unavoidable

Where does Road Film come from?

Oils and other fluids that drip out of cars, truck and suvs accumulate on roads and highways over time.

When it rains, these accumulated oils and other fluids mix with the rain and are then splattered all over your car in effect staining you're entire car from top to bottom. The highest concentration of road film accumulates on your wheels, tires and lower body panels.


Just look in the parking space of any parking lot...

Motor Oil, Transmission Fluid, Gear Oil and other fluids

These outlined areas show where fluids have dripped off engines and transmission, even radiators and accumulated to the point that the pavement has been permanently stained.

It's also on roads and highways...

The oil stain line that runs down the middle of the road...

The dark line down the middle of the road
It's the darker, line down the middle of roads and freeways where most of the oily fluids accumulate as car, truck and suvs drive down the road.

Now that you've read this article and looked at the above pictures, you'll remember this every time you look down the road you're driving on.


Remember, oil and water don't mix
When it rains, the cars in front of you spray the rain water mixed in with these accumulated oils onto not only your car's paint but the wheels, tires, glass, plastic, cloth tops and vinyl tops.

If it's on the outside of the car then it's getting coated with oily road film.


Road Film builds up over time..
Oily road film builds up over time and because this film is oily or sticky it attracts dirt. This can be the dirt in the air or also in rain water that's splattered onto your car from the cars driving in front of you.


Can't always be seen...
Because the dirt staining effect caused by road film build up slowly over time it's not always easy to see, especially on black and dark colored cars, but don't be fooled, if you drive in the rain your car is getting coated in road film.


The solution to the problem?
Washing your car will remove any topical road film. The problem is the dirty, oil film will tend to migrate into any voids, pits, pores or interstices in your car's paint at least to the point that normal car washing won't remove it.


It's pretty easy to remove road film, all you have to do is periodically use one of the below approaches,

Use a quality cleaner/wax or AIO. The cleaning agents and/or abrasives in the cleaner/wax will remove any road film that washing could not remove.

Use a dedicated polish by hand or machine. Any high quality polish will effectively remove any built-up road film. Just be sure to apply a wax, sealant or coating afterwards to seal the paint.



UPDATED - July 8th, 2021

A few weeks ago I used my own car to use and then review a new car wash. It had been months since I had washed the car. During this time I have driven this car in a lot of rainy weather. Below the pictures CLEARLY show you ROAD FILM. And over time, this film IMPACTS ONTO the car so it doesn't all wash off. It takes some form of chemical decontamination and machine polishing to remove it 100%

As I wash the car you can visibly see a layer of road film being removed.






She's a dirty girl...

Look carefully at the dirt level on the paint...

See it?

See the vibrant white color where I've ran the mitt over the paint? Then look in front of this area and you can easily see just how dirty this car was. :wowwow:

The above pictures taken from this product review.

Review: DP GR4 Graphene Wash





Road Film... if you drive your car in the rain it's on your car...

 

[Mike PhillipsMike Phillips is verified member.]

Here's a few articles that share various ways to remove road film...


Here's why you need to polish paint...

Dirt in Paint or DIP - Stained Paint - Dirt Embedded Paint

Here's the picture, not the difference in the color of green on either side of the black line...

The car above is Wayne Carini's 1953 Hudson



How to remove stains and embedded dirt out of paint

The dirt you see on the pad in my hand... (the pad started out white)

Came from this CLEARCOATED car...

The paint is clear and the brownish color is years of dirt staining that builds up ON the paint and doesn't wash off. It does come off when you use a compound, polish or cleaner/wax.




How to clay, clean and wax paint by hand with Pinnacle Paintwork Cleansing Lotion and Pinnacle Signature Series II Carnauba Paste Wax

While claying will remove above surface bonded contaminants, Pinnacle Paintwork Cleansing Lotion will remove embedded road grime and pollutants as you can see when we compare the applicator pad we used to a brand new, clean applicator pad.

The Lesson White Paint Teaches Us

 

[Nick McKees37]

Excellent article Mike. :dblthumb2:

I would like to add another way to remove stubborn topical road film, and that's with a paint-safe chemical cleaner. A great example is Detailer's Road Kill Bug Remover. While this product was primarily formulated as a spray-on bug and tar remover, it also works as a great "booster" to your car wash solution. A couple ounces will dramatically increase your soap's cleaning ability; you don't have to worry about it stripping a good quality wax or sealant either.

Detailer’s Road Kill Bug Remover

 

[jankerson]

Most likely the reason why I hate driving my cars in the rain.

Isn't it possible though that if the cars finish is properly maintained like people here on AG that washing and going over with a quality QD product would lessen the effects?

 

[Mike PhillipsMike Phillips is verified member.]

Most likely the reason why I hate driving my cars in the rain.

Isn't it possible though that if the cars finish is properly maintained like people here on AG that washing and going over with a quality QD product would lessen the effects?

Of course!

And this is something I practice all the time with my truck as it's a daily driver...

Frequent Car Care is Easy Car Care


Keep a waterless wash and a spray wax with some clean microfiber towels behind your truck's seat or wherever you can in your driver...

My article called The lesson white paint teaches us actually goes into detail about paint getting dirty...

 

[jankerson]

Of course!

And this is something I practice all the time with my truck as it's a daily driver...

Frequent Car Care is Easy Car Care


Keep a waterless wash and a spray wax with some clean microfiber towels behind your truck's seat or wherever you can in your driver...

My article called The lesson white paint teaches us actually goes into detail about paint getting dirty...

That's what I figured.

That White paint thread is my favorite thread here on AG. :xyxthumbs::xyxthumbs:

But then I am bias because I own 2 white vehicles. :dblthumb2:

I will NEVER own another Black car...

 

[Mike@DedicatedPerfection]

Thanks for sharing Gentlemen. Being here in Germany my car is subject to this road film everyday as I rely on it to get me to work. Also the weather is very unpredictable.

Unfortunately my car is a lot dirtier now than what I care for.

 

[Pureshine]

Very nice thanks for sharing this

 

[Scott@IncrediblyDetailed]

Great article. Something I never thought of.

 

[PiPUK]

Nice article Mike.

This is something which seems to be much more widely considered over here in Europe. We have a whole industry built around TFRs or Traffic Film Removers. The basic product type is strongly to extremely alkaline, the need for touchless cleaning pushes to the stronger end. In practice, many are actually rather similar to what you might use to clean your oven. 'Detailers' have traditionally shunned TFR products as being somehow evil but such products are now commonplace since the detailing/valeting brands are wise to this and have changed the names (and often diluted the nastier products).

 

[silverfox]

The Europeans are blowing us away in terms of using road grime film removers safely on car paint. If you look at those types of products offered in this country they are almost all from British companies who have exported them here.

 

[drvnbysound]

This makes me want to call in sick on rainy days

 

[PiPUK]

The Europeans are blowing us away in terms of using road grime film removers safely on car paint. If you look at those types of products offered in this country they are almost all from British companies who have exported them here.

Safety is, of course, a relative term. Many of the TFR products are extremely corrosive and are well known to cause issues if used incorrectly, especially on trims. This is one of the topics I used to bang on about all the time. The highly caustic products are cheap and effective but the risk to sensitive areas makes them, IMO, unsuitable for high end vehicle care. In that application, there are alternatives which are miles safer albeit at the expense of needing to be used at higher strength (in other words, the cost per use is higher). Unfortunately, not many of the new detailing brands know about that sort of thing!

 

[SR99]

It's worse in hot dry climates where it seldom rains and never snows. Much longer time for the films to build up on the roads between rains. The roads can get icy slick from the oily films, believe it or not.

During the rain, it's also the water from the soaked road splashing the underside of vehicles and bringing more new grit and films onto the road surface--not just what was there on the road before the rain.

Right after a rain, as the road surface begins to dry, I've noticed you can hear immensely more grit hitting your car (raised by the wheels of your car and cars you pass) due to the above, so I avoid driving right AFTER a rain too.

Of course, sometimes you have no choice.

 

[drvnbysound]

It's worse in hot dry climates where it seldom rains and never snows. Much longer time for the films to build up on the roads between rains. The roads can get icy slick from the oily films, believe it or not.

During the rain, it's also the water from the soaked road splashing the underside of vehicles and bringing more new grit and films onto the road surface--not just what was there on the road before the rain.

Right after a rain, as the road surface begins to dry, I've noticed you can hear immensely more grit hitting your car (raised by the wheels of your car and cars you pass) due to the above, so I avoid driving right AFTER a rain too.

Of course, sometimes you have no choice.

I've definitely experienced the icy slickness on a summer day after a rain shower... It was a number of years ago, but I was taking a right (or trying to) when I slid across the road past the turn that I was supposed to make. I stopped just short of the drainage ditch on the other side! Luckily there were no other cars around.

 

[Mike PhillipsMike Phillips is verified member.]

It's worse in hot dry climates where it seldom rains and never snows. Much longer time for the films to build up on the roads between rains.

Completely agree.

The roads can get icy slick from the oily films, believe it or not.

I know I've experienced this exact thing... how the road can be slippery after raining when previously there's been a long dry spell.

Always a good idea to be alert to this point.

 

[PiPUK]

Whilst hot and dry gives time for films to build up on the roads, it tends to mean that the films are less inclined to transfer to vehicles. I know it is anecdotal but UK vehicles are much dirtier beasts that those I have seen in arizona or california. Yes, there is particular soiling including mud and similar but this contributes to the film which builds on your vehicle as it is combined with the oily character or the film and thus does not rinse off.

It seems to me that this also tends to be supported by the fact that UK has a large industry built around highly caustic TFR products whereas this seems to be notably less (from discussions on here) in the US.

 

[KBsToy]

:urtheman:

 

[Mike PhillipsMike Phillips is verified member.]

Whilst hot and dry gives time for films to build up on the roads, it tends to mean that the films are less inclined to transfer to vehicles.

I agree.

I know it is anecdotal but UK vehicles are much dirtier beasts that those I have seen in Arizona or California.

I agree with this too...

I have a unique perspective on this topic as I lived most of my life in Oregon, where it rains a LOT. Then moved to Southern California in the coastal area and later to the Mojave Desert where it hardly ever rains, (in both places, near the coast and in the desert).

Cars don't have near as bad a road film problem in SoCal or in the desert as they do in wet, rainy Oregon.

Cars do still get dirty however as I show in this thread,

Here's why you need to polish paint...


My buddy Mike owns this really cool 1932 Ford Phaeton with yellow paint that to the average person looks pretty good. But a little polishing using a tape-line shows why all of us need to periodically polish the paint on our cars, especially our daily drivers, and the reason for this is because the paint becomes stained with a film of dirt that clouds the true color of the paint.

Here's a section I've taped off on the cowel because me and one of our forum members already buffed out the hood when he stopped by to test out polishers.

On the left I've clayed the paint and then machine polished it twice and then applied a coat of wax. You can clearly see the left side is now a brighter color of yellow and the right hand side has what appears to be grayish film over the paint.

Here's the same picture above with graphics....

Of course I finished polishing the rest of the car to test out some new products...

Products worked well and now the dirt staining has been removed off the entire body and a coat of Max Wax has been applied.

The paint on your car gets dirty too...

The car in the pictures above is a garage-kept, sunny day only street rod, yet... the paint was still stained with dirt.

If the paint on a car that is always stored in a garage except for sunny days gets dirt stained paint, what do you think happens to cars that are daily drivers?

How about cars that are daily drivers but are never parked in the garage?


That's right... the paint gets a dirt film over it and for this reason in order to maintain the paint and see the true color you need to periodically deep clean the paint with some type of paint polishing process. Any of these approaches will remove the dirt staining over the paint,

• Using a one-step cleaner/wax
• Using a paint cleaner also called a pre-wax cleaner.
• Using a compound followed by a polish
• Using a medium, fine or ultra fine cut polish

If the owner of the above car had not used one of the above and instead used a finishing wax, or a finishing sealant, that is a product with no ability to clean the paint, what they would have done is simply "sealed the paint" and continued the staining problem.


Medium to dark colored cars
It's pretty easy to use a tape-line to reveal dirt staining on white and light colored cars but if you were to do this on a medium to dark colored cars, chances are good your eyes would not detect the change in color to the paint.

That doesn't mean the paint on dark colored cars isn't covered with a film of dirt, it just means you and I can't see it. It's there however, and it's important to periodically polish the paint to remove the built-up film of dirt and other contaminants.

Polishing the paint will restore clarity to a clear coat and it will restore the full richness of color to a single stage paint.

It will also prepare the paint for your choice of a wax or sealant.

If you choose to use a paint coating, you'll need to do an extra step to prepare the paint for the coating and it's always a good idea to follow the manufacturer's directions.



Now that you've read this article and looked at the pictures...

When is the last time you polished the paint on your daily driver?


It's probably polishing time...

It seems to me that this also tends to be supported by the fact that UK has a large industry built around highly caustic TFR products whereas this seems to be notably less (from discussions on here) in the US.

I'd agree with you on this too... I'm thinking we're more lucky on this point than our friends across the pond.

 

[Mike Honcho]

Bumped for the excellent and detailed info!