How to reduce Road Noise in a Car in 6 Simple Steps


Some cars are simply louder than others, and that’s especially true for older models. From traffic noise to rain thumping on the roof; these sounds can turn a pleasurable ride into a major hassle.

So if you’re looking for a way to increase your driving enjoyment, here are a few sound deadening methods that work really well.

1. Identify the main noise sources

Ask yourself a simple question – where does most of the noise when you drive come from?

Here are the most common sources:

  • traffic and wind noise
  • road noise from under the car
  • engine noise
  • exhaust noise

When you know where the sound is coming from, you can strategically place sound insulation material inside the car cabin and in other places.

2. Soundproof the floor

To minimize the amount of noise you can hear coming from the engine, the exhaust and incoming traffic, the most important thing you can do is soundproof the floor of the cabin.

The car floor acts like a large sound diaphragm, making the noise from the road resonate throughout the inside of the car. The FatMat sound deadener is commonly used for soundproofing almost all areas in the car and especially the floor.

It’s pretty simple to install. First take out the floor mat, then apply the FatMat on the floor. Make sure that it sticks well before returning the mat back on top. The cool thing about this product is that it’s self-adhesive, so there is no need to use any additional glue to make it stick.

To see how others have done it, check out this video:

How effective is FatMat?

This method works really well for sound insulation. Also, the larger the area you cover, the better the results will be. You can place the material in the front, and in the trunk as well.

By covering the trunk area you’ll deaden the noise coming from the rear wheels. I recommend doing that if you have a large flat trunk that emits a lot of noise and vibrations. If you don’t have a large flat trunk, this is optional and will make less of a difference.

The Double Method  for heat insulation (optional)

If you want almost perfect silence while you’re driving AND you want to get rid of the heat coming up from the front panel of the car, then this method is for you. It involves adding reflective insulation under the sound deadening mat.

Reflective insulation is a powerful blocker of heat, and you can expect an almost 100% reduction of heat from the front panel, which of course, separates you from the engine.

This reflective automotive insulation has been the most popular and best rated for some time now. Considering the insulation is pretty thin, many users are surprised at the huge difference it makes. You could use this insulation alone, but to really improve the noise reduction of the first method, it’s best to use this one UNDER the sound deadening mat. So install this insulation first, and then cover it with additional sound deadening insulation.

The double method will reduce by double the noise and heat emanating from the engine and the floor.

3. Soundproof the doors

Some cars have really thin doors, so it’s no wonder that road noise comes inside the cabin through them as well. Jeeps and older Toyota models are especially known for having thin doors, so if you own one of these bad boys it’s definitely a worthwhile investment.

This project takes a bit more time and effort than soundproofing the floor. Because it’s necessary to remove the panels from the doors in order to fit in the soundproofing material.

But it’s not complicated at all. There are many video tutorials available online that show you exactly how to do it. I’ve covered all the vital information in my car door soundproofing guide.

4. Soundproof the car engine

The car engine is another really big noise producer. It causes more of a rattling sound, so in order to reduce the sound, you can use the FatMat.

In order to soundproof the car engine, cover the inside of the hood with the mat. You’re done! To see how it should look like when you’re done, check out this video from the 2:00 mark.

5. Soundproof the car roof

You should soundproof the roof of the car if you want to minimize the traffic and wind noise, as well as the thumping sound of rain. It will also help to improve the acoustics in the car, along with the other soundproofed areas.

You can use FatMat or any similar sound deadener on the roof as well. The procedure is similar to soundproofing the car floor. You’ll need to remove completely or partially the padded layer and cover the inside with the sound deadener. Using a self-adhesive product will really help make this easier if you don’t want to remove the padding completely.

This guy used Noico sound deadener to soundproof the roof of his Mazda. It’s very similar to FatMat so you can use either one of these products. A very useful tutorial that anyone can follow to success:

And here is the second part:

6. Reduce the exhaust noise

If you have a more powerful engine, you might be dealing with a lot of exhaust noise as well. Some people love to hear the power of their engine pumping through the exhaust in the form of sound waves.

But others, like myself, are not a**holes and we don’t like to flex our muscles that way and disturb others on the road. If you belong to the not-a**holes group, you can reduce the exhaust noise by installing an exhaust muffler or an exhaust silencer.

Something that I only recently discovered are external muffler silencers that you can attach on the exhaust from the outside. Works like magic and they’re super easy to install! I’ve covered all of these methods in detail in the how to reduce exhaust noise article. It’s a great read!

How much road noise reduction can you expect?

As I said before, it depends on the car, and also on how much soundproofing you do. If your car is older, using the sound deadening mats on the floor will make a huge difference. If you have a newer car, it’s probably not as loud to begin with, so you’ll have an even easier job at minimizing road noise.

Other than that, the results will also depend on how many of the critical areas you soundproof. If traffic noise is your main concern, definitely soundproof the car doors as well. With that being said, I hope these simple soundproofing tips will help you create a more pleasurable driving experience.

FAQ:

1. How can I measure the level of sound in my car?

To know how big of a difference your soundproofing efforts made, you can measure the noise in your car by using a sound level meter. It’s a small device that can measure the decibel levels in the car (and any other area). So I advise turning it on and taking your car for a spin before you do any soundproofing work, and also after you’re finished soundproofing. That’s the most objective way to know how big of a difference it’s made.

I advise getting this sound level meter because it can measure high and low frequencies equally well. The random sound meters that cost around $20-$40 unfortunately provide only general estimates. These cheaper options can still be useful, but you’ll have to rely on your ears as well to determine the full results. Sound meters are pretty fun and useful, and soundproofing professionals and enthusiasts use them to determine the success of their projects.

2. What to look for when buying a quiet car?

If you’re buying a new car and are concerned about noise, here are some things to take into consideration:

THE SUSPENSION – Softer suspension will “soak up” more of the vibrations from a hard road. Many cars nowadays are built with too stiff suspension, probably to make their car feel like racing models. But stiffer suspension has some benefits such as increased tire temperature for better traction and improved handling response. How to know whether the car has soft or stiff suspension? Inquire about the characteristics with the seller and check them up online. Here is a great article for understanding the difference between the two.

THE ENGINE – Electric engines are the quietest, followed by the hybrid engines (mix between electric and gas/petrol). The loudest engines are either diesel and gas/petrol engines. Diesel engines are quieter now then they used to be, but they are generally noisier than gas/petrol engines at lower speeds. Other than the actual engine, the soundproofing material used in the engine compartment can make a big difference as well.

THE TIRES – Your choice of tires can have a big effect on road noise. Generally speaking, narrower tires and smaller wheels will produce less noise than larger ones. The rubber that the tires are made of can also be different, resulting in different noise levels. Harder tires will produce more noise than softer ones. Even the tire patterns can make a difference, causing a different amount of traction and therefore being louder or quieter. Some tire manufacturers actually show the dB levels produced by their tires, so if that information is available definitely check it up. The other way of finding out which tires are the least noisy is to ask the experts in tire workshops and exchange information with other drives. Changing tires to reduce road noise is something you can do without buying a brand new car, and it can make a difference.

THE WINDOWS – If you’re worried about noise falling through the windows, it’s best to get laminated windows. Some manufacturers offer laminated windows, a combination of layered glass and plastic material that provides additional soundproofing. Laminated windows can block a significant amount of traffic and wind noise when compared to standard windows. Taking a car with and without laminated windows for a test drive is the best way to see if the difference in noise reduction is worth the money.

THE CHASSIS – Chassis is the base frame of a car. The chassis in sports cars is usually lower than those in regular cars. The lower the chassis, the closer the road noise will be to your ears. Keep that in mind before buying a low car!

LARGE CARS vs. SMALLER VEHICLES – Larger vehicles such as trucks and SUVs have a larger surface, and this larger surface generates more wind noise. The large space in the back can also act as a huge sound diaphragm if not soundproofed correctly. As far as road noise is concerned, smaller vehicles are usually quieter due to their very design.

3. Dynamat for car soundproofing?

Dynamat is often recommended on car soundproofing forums and many Youtubers have used it as well. The issue I have with Dynamat is that it has the same sound deadening effect as the other similar products, but it’s more expensive.

The only difference is the brand name. The company has been around for a long time and people trust it more than other brands. That’s all there is to it. So if you want to save some money, I recommend using FatMat or Noico instead. But you won’t go wrong if you use Dynamat either because it’s essentially the same material.

4. Why is my engine running louder than usual?

There can be many reasons for the engine becoming too loud. It just might be screaming for help and hoping that you will listen! The noise is typically connected to a failing exhaust system:

A FAILING MUFFLER – Mufflers are exposed to heat and pressure every time you drive. They can also get damaged by the weather, the road grime and salts, and develop rust and cracks. This will make the engine run louder. Some symptoms of a failing muffler are drop in gas mileage and increased exhaust fumes. If you find this to be true, replace your muffler (possibly with a quieter one!), or drive your car to a professional mechanic.

A FAILING CATALYTIC CONVERTER – Converters are necessary for burning off hydrocarbons in the exhaust. If the converter fails, there will be a rotten egg smell coming out of the exhaust. If the catalytic converter becomes completely blocked, the car will not run at all.

A BROKEN TAIL PIPE – The tail pipe is connected to the muffler and through it the gases and fumes are expelled. If the tail pipe has holes and cracks in it, or falls of entirely, noise levels will inevitably increase.

These are the most common reasons for increased engine noise. To check out other possible reasons, have a look at this article from YourMechanic.com.

Final Thoughts

If you follow the soundproofing recommendations provided in this article and use the correct soundproofing material, you can significantly reduce the amount of road noise, traffic noise and wind noise coming into your car cabin. Hope this helps!

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