Car Undercoating Soundproofing: Does It Reduce Noise?

car undercoating soundproofing

Each one of us spends a significant part of the day in our vehicle.

Normally we try to exclude all the noise that comes along, but there are days when it’s simply more nerve-wracking than usual.

We try to think of as many ways as possible to deal with it without spending a fortune.

Have you heard of car undercoating? Some people swear that it’s the best thing to fix the unwanted sounds issue. 

Let’s see what it is and how does it work. Perhaps this could be a solution to your problems. 

  • Can be used on RVs, trucks, vans
  • Black protective coating
  • Best match between quality and price
  • Reduces metal vibrational noise
  • Effective for wheel wells and undercarriage
  • Great for soundproofing
  • Applicable on doors, panels, decks
  • Low VOC Formula - Dries quickly
  • Simple and effective
  • Contains no asbestos fiber
  • Protection from dust, moisture, corrosion, cold, you name it!
  • An effective sound barrier to reduce noise

What is car undercoating?

car undercoating soundproofing

First of all, let me explain to you what undercoating means.

When you want to stop corrosion in vehicles before it even starts, what you need to do is undercoat it.

So, undercoating is putting some sort of physical barrier between the road debris, salt, grimes etc and the exposed underbody.

The reason I mentioned these is that they cause far more problems than the litter.

These are full of different chemical compounds which get drawn up into the vehicle. That leads to corrosion.

However, once the corrosion becomes visible, your car is already in a deep problem. The effects of corrosion are already widespread.

How does Car undercoating Soundproofing work?

Undercoating is also one way of rustproofing the car.

There are differences between them. Now, you may wonder what it has to do with soundproofing.

You see, undercoating not only protects your car from rusting but reduces the noise coming from the road and engine as well.

How does Car undercoating Soundproofing work?

How so?

Well, the undercoating is applied to those surfaces which are highly exposed to the road, such as wheel wells and the underbody.

When you undercoat a car, you prevent the debris from making the contact with metal. That means less annoying noise!

Steps to follow before undercoating

The process of undercoating can be done in a car workshop or you can do it yourself.

If you decide to do it yourself, there are two phases to go through:

  • Cleaning
  • Preparation

The first phase, cleaning means you should remove all the dirt and rust.

Begin with scrubbing the car’s underside and the wheel rims. You can use soap and water to do so.

Hose it down with water afterward and if necessary, repeat the previous process.

You can even use rust remover.


Once you clean it, dry it with a towel or let it sit outside for a few hours.

As for preparation, put the handbrake up, you don’t want your car to roll off while you’re undercoating.

Then elevate it on jack-stands and proceed with the next step-undercoating.

How to undercoat car and soundproof it?

Once you have finished the two previous phases, the next to do is undercoat your car.

Do it slowly and make sure you don’t miss a single spot.

After all, the main point is to protect your car from rust, soundproofing is what goes along.

Still, it’s important to do the job well, so that you get maximum effects of undercoating.

Once you finish it, give it some time to set.

It usually takes a day or two. Just to add, the time required for the undercoat to set well also depends on climate.

The amount, that is, the number of cans depends on the size of your vehicle.

There are many different types of this spray, and I shall give you a few suggestions.

Car undercoating pros 

Undercoating your car has following positive sides:

  • Protects your car against the rust
  • Extends the lifespan of your car
  • Reduces the noise

Dealing with corrosion the best way already is big deal, and the soundproofing comes as a significant bonus.

You will agree that it is important to have peace of mind while driving, at least by solving the unwanted noise problem.

The best thing of all is that undercoating your car is a cost-friendly process. Moreover, it’s very simple and relatively quick.

All these benefits mean that you will have more time to enjoy a peaceful and quieter drive in your protected car.

Car undercoating cons

I say “cons” may not be the most appropriate word here, but I’ll let you decide what the best name for these two is.

Car undercoating may not be the solution in the following situations:

  • If you have a used car
  • If your car is already full of rust
Car Undercoating Cons

The best timing for undercoating is when your car is new because there aren’t obstacles such as corrosion, residue, and debris.

When a car is used, it takes more time and money to prepare it, even repair the metal if there’s too much rust.

But, you still get the soundproofing, and when you count that all together, the overall cost is still acceptable.

The best car undercoating sprays for soundproofing

Here comes the list of few suggestions.

I took various aspects into consideration, such as price, quality as well as the option to use it on different types of vehicles.

To be clear on this- they are more or less good for undercoating, they really do the job, but I also took the level of soundproofing as an important parameter for making this list.

The Best Car Undercoating Sprays For Soundproofing
  • This 3M spray is number one on my list as it represents the best match of quality and price. You can also use it on RVs, trucks, vans. Moreover, it’s excellent in dealing with all the distracting sounds coming from the road and the engine. You need to apply lots of it if you want to see the noticeable results.
  • Spectrum Liquid Sound Deadening by Second Skin Audio is the best option if soundproofing is your number one priority. It can be used on any metal surface to reduce vibrational noise, making it an excellent undercoating for any car looking to cut down on road noise. It’s also very effective when sprayed into the wheel wells.
  • Simple and effective- two words which describe the best this CRC spray. The low VOC formula it has means this spray dries off quickly. It gives a noticeable difference when it comes to soundproofing. You can apply it on doors, panels, decks as well.
  • This PlastiKote spray covers wide fields of protection. Dust, moisture, corrosion, cold, you name it! Moreover, it reduces the outdoor noise significantly. It takes a while for it to dry, so be patient.

As I said, there are many more, but I picked these four, as soundproofing effects are what matters the most here to me.

Some alternatives to car undercoating


Undercoating sprays do make the difference, but still, there are people looking for more than just a few decibels less.

There are some alternatives which can provide a bigger difference such as:

It’s quite natural that a car starts making more and more noise as the time goes by.

The key is to keep all the parts tight and checked on a regular basis. That minimizes the unwanted sounds.

Applying any of the solutions for soundproofing won’t do any harm.

Quite the opposite, you will notice the difference which will result in a less stressful drive.

I suppose the main parameters for your choice will be your budget and the exact level of noise you would like to reduce.

How to Make Your Car Quieter

Final thoughts on car undercoating soundproofing

All in all, undercoating does make the difference when it comes to soundproofing.

Speaking in terms of science, it reduces the noise at least up to 5 dB (decibels), perhaps even more than that.

A decibel here, a decibel there, the difference exists and it’s all that matters.

Learn more about the decibel scale here.

I say go for it. The solution may not be a long-term one but still doesn’t cost a fortune.

As a matter of fact, if you undercoat your car on regular basis, you ensure the constant protection both against rust and unwanted sounds.

Have you already tried it? Has the undercoating worked for your car? Share your thoughts and experiences with me!

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