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The Best Loud Car Horn 2021

Car Horns

OEM car horns can be bought from the dealerships but you’d only do this if you like throwing money away. OEM horn replacements are fine if you don’t want to increase the noise, but if you are reading this article, you most probably want the loudest on the market.

The best car horn that is loud and easy to install is the Stebel Nautilus 11690019, which works with any 12 volt system and outputs 139 dB of noise. The loudest car horn is the mighty MPC B1 (0419) train horn kit, which will scare anyone nearby.

You have the choice of choosing a loud car horn with or without a compressor. The benefits of a car horn with a compressor is that it will be much louder. However, it requires a little bit more effort to install but its totally worthwhile.

Aftermarket Car Horn Comparison

Best Car HornsDecibelsType
Stebel Nautilus Compact139dBSingle
MPC B1 (0419)150dBQuad
Wolo (419) Bad Boy118dBSingle
HELLA 003399801 Twin Horn118dBDual
Marco Tornado151dBSingle
Zento Deals Trumpet Air Horn150dBSingle

Installing an aftermarket car horn replacement isn’t the first modification you think of doing but its worth doing. I personally use the Stebel Nautilus Car Horn in many of my cars and I’ve had lots of fun as well as saving myself from being crashed into on multiple occasions. The below video is how the horn sounds as it approaches you.

The majority of loud car horns are simple upgrades that don’t require a compressor for producing a loud noise. Some may require small adjustments depending upon your vehicle but overall, its an easy modifications for the average car owner.

Below is a list of the best loud car horn upgrades that are straight replacements and some of the loudest on the market.

The Best Loud Car Horn Upgrades

1. Stebel Nautilus Compact Mini Air Horn

The Stebel Nautilus is one of my personal favorite car horns and I have installed several. It has a unique sound from the twin tone harmonized horn that outputs at 139 dB.

It’s a compressor based car horn that has a compact design to fit in all locations under the bonnet. The compressor itself is self-contained and the horn is a direct replacement.

Other features of the Stebel Nautilus Horn include:

  • Noise output of 139 dB
  • Water resistant compressor
  • Requires a 12V connection
  • Suitable for a range of vehicles
  • Black ABS finish
  • Supplied with a relay

The Stebel Nautilus is a cheap loud car horn replacement that offers excellent value for the money. The compact design makes it easy to install and suitable for a variety of vehicles.

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2. MPC B1 (0419) 4 Train Horn Kit

The MPC B1 (0419) 4 is by far the most popular train horn kit on the market. It’s ideal for cars, trucks and other vehicles and is able to get the attention of anyone nearby.

Included with the train horn kit is a 12 volt 110 PSI compressor, 3 liter tank, pressure switch, wiring kit and other accessories.

Other features of the MPC B1 (0419) Train Horn include:

  • Outputs over 150 dB
  • 110 PSI compressor
  • 3 liter air tank with switch activation
  • Must be kept within a dry location
  • Comes with all the accessories for installation
  • Universal and suitable for any vehicle

The MPC B1 (0419) is by far the loudest electric car horn that is universal and able to fit any car. Although it does come with an expensive price tag and require a compressor, it’s the ultimate train horn kit that you won’t regret buying.

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3. Wolo (419) Bad Boy Loud Car Horn

The Wolo (519) Bad Boy is a fairly popular replacement car horn that the brand claims is twice as loud as factory horns. It’s a one piece construction that is easy to install and a direct replacement for many factory horns already installed to your car.

In terms of the loudness of the horn, the brand states that it produces 118 dB, which is produced through a powerful dual tone.

Other features of the Wolo (519) Bad Boy include:

  • Noise output of 118 dB
  • Powerful dual tone output
  • One piece construction
  • Easy to install
  • 12V system
  • Maintenance free

For those that want a simple car horn upgrade which is a direct replacement, the Wolo 519 ticks all the boxes. Although it doesn’t have the loudest output, its certainly louder than factory horns and it also looks great for horns that are exposed.

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4. HELLA 003399801 Twin Horn Kit

What is better than having one horn? Two of course. Hella have produced a car horn kit with one high-tone Supertone horn and one low-tone Supertone horn. This kit comes with two mounting bracket and offers outstanding value for the money.

Other features of the HELLA Twin Horn Kit include:

  • Noise output of 118 dB
  • Backed by a one year warranty
  • Similar tone to Mercedes & BMW horns
  • Twin horns that are available in red, black or yellow
  • Installation accessories included
  • Can be installed vertically or horizontally

The HELLA car horns are the best cheap aftermarket replacement that is available in red, yellow or black. Not only do they produce a loud noise output but they are also backed by a one year warranty for complete peace of mind.

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5. Loudest Car Horn by Marco Tornado

The Tornado Car Horn by Marco is the loudest car horn you can buy at 151dB. This not only beats the competitors, it dominates them by a country mile. There is no additional power supply required and this car horn can fitted to all cars with a 12 volt electrical supply.

Other features of the Marco Tornado Horn include:

  • Output 151 dB
  • Constructed of heavy duty materials
  • Powered by a compressor
  • 12 and 24V
  • Excellent cold weather performance
  • Two harmonized tones
  • Includes a two year warranty

The Marco Tornado is an excellent all-round option that combines performance and value for the money. It’s also backed by a two year warranty for complete peace of mind, which is a big bonus when compared to similar priced alternatives.

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6. Zento Deals  Single Trumpet Car Air Horn

Not all car horns need to be mounted within the engine bay. You will often see cars, trucks, SUV’s and boats with a trumpet style that is often mounted on the roof. This Zento Deals car horn kit is a great example that outputs an impressive 150 dB of noise when activated.

Other features of the Zento Deals Horn Upgrade include:

  • Powerful 150 dB output
  • Universal and suitable for all vehicles
  • Polished red compressor and shiny horn
  • Includes all mounting hardware and hoses
  • Powered by a 12V DC supply
  • Easy to install

Overall, the Zento Deals car horn kit is a powerful yet affordable replacement that provides great performance. If it’s not a requirement for the horns to be hidden, the trumpet style may be a great alternative.

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Car Horn Buying Guide

As with most vehicle components, car horns will not last forever and eventually you will be required to replace the part. Car horns are an essential part that is required by law in order to remain street legal.

The choice of noise outputs between horns differ, with many simply wanting a direct replacement and others wanting the loudest car horn possible.

As you can see from the image below, they do become fairly corroded overtime. This horn was replaced from a 20 year old vehicle and took just a few minutes to switch over the part. There are a variety of car horns available from small to large and its just a matter of preference and whether the horn is compatible.

To help you make an informed buying decision, we have produced the detailed buying guide below regarding car horns.

Brief History of the Car Horn

Perhaps the most notable car horn, called the Klaxon, was invented by Miller Reese Hutchinson, an employee of Thomas Edison.

He became alarmed by the increasing number of accidents happening in New York City and took it upon himself to invent a horn that had a loud piercing alarm that sounded either manually via a crank or motor-powered battery.

These types of horns carried on until the early 1930’s era, which is when they replaced by the more convenient electric powered horn.

Loudest Car Horn

What is the Law with Car Horns in the US?

Car horns today can be outrageous, to say the least. Take your pick from bells to cat calls, train whistles, to full orchestra arrangements. Pay the price, and you can have it. This is not to say that they are all legal because the laws differ from state to state. For example, many states define 110 dB as the street legal limit.

Most of states have one primary rule with regards to car horns, which is that they can not emit an unreasonably loud or harsh sound. This is normally understood to be louder than 100 to 110 decibels. This is compared to a train horn which normally operates at 130 to 150 decibels. A few states and their regulations are listed below:

For more information regarding car horn laws, you should check your state’s DMV or BMV website. It is very unlikely that a police officer will have a decibel meter waiting to catch you out but if you use the horn irresponsibly, you may be fined.

loudest 12 volt horn

How to Install a Car Horn

If you are new to installing car horns, then don’t worry, it is fairly easy to do. It’s more a matter of finding everything and connecting everything properly.

Owning a digital multimeter is really handy for installing components such as a horn. This device will help you find continuity within wires if you cannot seem to power up the horn.

If, on the other hand, you are doing this in relation to damage that needs to be fixed such as an airbag, it is important that you have a professional to do the work.

It is fairly common for your cars computer to start firing error codes. This is because you are more than likely removing the airbag, which will trigger warnings such as the SRS light. After installing your new loud car horn, if the warning is still there, try removing it with a diagnostic tool. If it remains, check you have installed the horn correctly.

First, you need to find your horn, which is normally located on the radiator support or immediately behind the radiator and the grille. A horn is normally circular in shape with two wires coming from it.

Disconnect the wires

The two wires that are connected to your horn are normally attached with metal connectors that simply slide onto the horn. If it is hard to remove these, you might need to press down on them to break any corrosion that might be holding them in place. Once you have them off, clean and replace them. Then try to sound your horn again.

Setting the replacement. If fixing your horn by cleaning it doesn’t work, or you want to replace it, you will need to remove the old horn. This is done by using a wrench to unscrew it from the body of the vehicle. Now buy a new one that is like the old, or by a universal horn of your choosing.

loud car horn

Check the fuses

While you have everything apart, and you have the opportunity, it’s a good idea at this point to check the fuses. The owner’s manual or looking your car up on the Internet will show you where your fuse box is. You need to locate the fuse that is for your horn.

Sometimes this is located on the fuse box itself, but otherwise, you can find this out from your owner’s manual. Sometimes you can remove the fuse with your fingers, otherwise, use a pair of pliers to pull it out. If the metal connection on your fuse is broken, your fuse has failed and needs to be removed. Buy a replacement from your auto supply store and replace it.

Check your airbag

Sometimes, if there is a problem with your airbag, the light on your dashboard will light and your horn will not work. If you think this is the problem, do not attempt to fix it yourself. Take your car to a professional to have it repaired. Make this kind of a repair yourself and you are taking your life into your own hands.

Replacing or adding an auto horn isn’t a hard repair to make, but it is important that you have a properly functioning horn.

Funny Car Horns

For use off the road, there are a number of “funny” car horns that are available. Personally, the all time favorite and the best funny car horn has to be the Dixie horn, which is a car horn everyone loves.

Interestingly, most states do allow owners to be in possession of these horns, and can even mount them to their vehicles, but they cannot be operable or they risk violations.


Replacing your car horn with an aftermarket alternative is a simple modification that is easy to do. There is a whole range of loud car horns available that can be used with or without a compressor. However, it is worth noting that using the loudest car horn you can get your hands on may not be street legal.

All of our recommendations cover a variety of horns that are either direct replacements to your original horn or fully blown electric train horns.

procarreviews author

Written By Dan

About the Author

Dan is an automotive journalist and owner of over 10 cars ranging from supercars, tuned cars, classics and your good old beater cars. He always likes to get his hands dirty with nut and bolt restorations or detailing sessions using the best products on the market.

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