There’s always been that thought that cruising along the highway is a fun and relaxing experience when the traffic isn’t too bad.
Drivers get an opportunity to pick up speed a little bit, enjoying the open road. However, that enjoyment can be sullied if a car is too loud on the highway.
Why is a car so loud on the highway anyway? Some of that is attributed to simply going faster, as a car will make more noise going 70 mph compared to 10 mph.
However, too much noise can be extremely distracting. These are the most likely areas where sound is coming from, and what can be done to fix things.
Tires

There are situations where drivers will feel like they can hear the tire tread on the pavement. If it is becoming a little too loud, this noise can be caused by several different factors.
For example, there could be too much cargo in the car, low tire pressure, worn-out tires, and more.
Make sure to check the tires out and see if there are any problems if the sound is only getting worse. Some cars have a light that comes on if the tire pressure drops.
If it seems to be an issue that will not go away, it is time to go to a shop and see what might be causing the problem.
Tires are pretty durable, but they eventually wear down just like anything else. They are under a good amount of stress on the highway, which can cause the noise levels to jump.
Engine Issues
Just about everyone knows that a car going at a fast speed means that the engine is not only running, but being put through a good amount of stress.
When on the highway, it is particularly important to ensure that all the smaller fixes are probably treated to ensure that the engine is running as quietly as possible.
There are a few common causes for a louder engine, so keep them all in mind when doing any type of checkups without the help of a professional.
Smaller engine troubles can turn into something much more serious if left untreated. That is why it is recommended to get the engine checked out whenever the noise climbs up in decibels.
It does not take any official measuring, as most will notice engine issues by quickly paying attention and listening. (Source)
Bearing
Bad bearings can cause a little bit of knocking underneath the hood. They can be loud and annoying, and if left untreated, it could cause an engine to seize up completely.
It can be a pretty costly issue if that ends up being the case. Get the bearings treated as quickly as possible, and the loud knocking sound will go away. When treated early, it is a relatively minor issue.
Muffler Problems

Even though it is not entirelly connected to the engine, people initially might think that a loud muffler is stemming from an engine problem.
Once it is realized that it is the muffler that is damaged or completely malfunctioning, it is time to make a replacement.
It doesn’t necessarily require a fast fix, but it does help with reducing sound and improving gas mileage.
A huge purpose of a muffler is to control sounds as much as possible. It also helps with fumes emitted from the car.
Cars without a muffler on them can still function, but they are going to be extremely loud on the highway, or anywhere else for that matter.
Getting a new muffler is a lot cheaper than having to fix an engine, so that is at least one positive when figuring out the muffler is causing the problem.
A brand new, high-quality muffler has the chance to make a huge impact on sound.
Oil
On the highway, there is a chance that you might notice some grinding or rubbing sounds every once a while. If that’s the case, it could be a strong indication that your engine oil levels are a bit low.
A monitor on most cars will allow people to keep track of that without really thinking, but if it has been a long time since an oil change, take it in and see if the sensor is not working.
Engines need oil to stay as lubricated as possible, so they are running the right way. It is very easy to blow off an oil change, but it will become a bigger issue as time passes.
Not only will it affect the engine’s performance, but it could make the car sound louder on the highway.
Torque Converters

Any automatic transmission car has a torque converter. It needs transmission fluid to work properly, as it will otherwise cause a lot of grinding noises any time the car is in gear.
It seems to be amplified a bit when it is on the highway and operating at faster speeds, so keep that in mind.
Tackling the Highway in a Quiet Manner
Driving faster is always going to be noisier than cruising along very slowly, but there are ways to make life a little bit better.
Don’t be afraid to explore a few different options and see which ones actually work.
There are plenty of fixes people can do on their own, but there’s also the opportunity to take it to the mechanic at any point in time.
The most important thing is to ensure that it is not an issue that will cause more serious problems in the immediate future.
If that’s the case, some louder noises could be the least of a person’s worries. Most cars will still be able to function just right with some added noise, but it is always better to be safe than sorry.
Sound Deadening Mats
Using sound deadening mats (Amazon) is one of the most versatile ways to make quick fixes without spending a ton of money.
Many different brands have sound deadening mats, and they come with everything that needs to be installed.
They are most commonly placed on the ground, but they can also be attached to the side of the car if need be.
These mats are pretty durable, which helps people who only want to make one initial investment and forget about it.
Sound Deadening Foam/Spray

Think of sound deadening foam and spray (Amazon) as a solution for those areas that can’t be reached by using mats.
This type of setup is much easier to put into small cavities, which can be very helpful. It doesn’t take much to put inside of an area like the door to help with sound deadening in general.
Foam and sprays are a little more expensive than mats, but don’t be afraid to use a combination of both if needed.
Sometimes it takes a combination to get everything properly solved with the sound quality.
Fix any cracks/gaps
It doesn’t take much for sound to have the opportunity to leak through one way or another.
It could be a slight crack in a window, or some separation in the trunk area that is causing the problem.
These need to be fixed for several reasons, including sound issues.
If it is a very loud sound that is seemingly coming out of nowhere, this very likely could be the culprit.
It is important to identify where the sounds are coming from and isolate them to make smart decisions.
Regular Maintenance

It can be a lot for some people to get in the habit of maintaining their car after purchasing.
It might not seem like the biggest issue in the world at first, but constantly having to do things like changing the oil, do maintenance checks all over the car, and more become more and more common as time goes on.
As annoying as it can be, regular maintenance can do a great job of ensuring that the car never gets too loud on the highway.
There are a lot of different ways to avoid loud noises by being proactive instead of reactive.
It might actually end up saving some money as well, because some of the fixes can be rather costly if they get out of hand.
Drowning Sound Out With Music
Music is just one way that people drown out sounds that are a little troublesome on the highway. It is no surprise that people turn up the volume when they ride along, as it’s harder to hear when going that fast.
This is a way to mask the sound, but a noisy car can actually throw off how music sounds in general.
If you really care about music when driving, it is worth investing in soundproofing material to help sounds come through clearly.
Otherwise, it could end up being pretty tough to understand what is coming out of the speakers.
Why a Quiet Car Makes a Difference on the Highway
Ultimately, people enjoy hearing the sounds they want to, and masking those that are nothing more than a nuisance.
There will inevitably be some sounds that are impossible to eliminate when going out on the highway, but it can be reduced to a tolerable level with some simple fixes.
Just remember that any sudden changes in sound are likely a reason to inspect the car in general. It could be a signal that something major is wrong with the car and needs to be addressed as quickly as possible.