Best Additive to Quiet Engine Noise

Engine noise can be annoying but it could also be an early indication of an expensive repair coming up. If you use the best additive to quiet engine noise you won't only have a quieter ride, you'll save on repair bills too.

Engine noise is something you can control. Sometimes it’s just a case of having a good muffler in place. But even then that’s not always enough. We would recommend that you get yourself a good engine oil additive designed to keep the engine running smoothly.

We’ve reviewed some of the best additives on the market for quieting engine noise.

We’ve also put together a buying guide for you that will walk you through some of the key points to consider before you buy.

Then we answer a selection of your most frequently asked questions about the best additives to quiet engine noise.

Best Additive to Quiet Engine Noise



DURA LUBE HL-41705-04 Severe Instant Quiet Motor Oil, 8-Ounce


When we saw what this motor oil was called, we knew we had to check it out - and we weren’t disappointed. This is an oil that does exactly what it says on the box. It silences both engine noise and transmission noise. And it does so immediately.

And it has a range of other benefits besides. It replaces any lost additive content between fluid changes, and it lubricates the engine parts, helping to reduce friction, and engine temperature. (Lubrication is a great way to quiet noisy strut mounts too.)

This in turn serves to prolong the engine’s lifespan, and give you more miles per gallon, saving you money on fuel. And it reduces engine sludge to boot.

This is all thanks to its advanced SR₃ technology, a revolutionary molecular formula designed to prevent metal to metal heat and friction.

It can be used in any type of engine, whether it’s diesel, gas, or even hydraulic.

It contains no solids, and is non-corrosive, making it perfectly safe to use, and using it will not void your manufacturer’s warranty. And it can either be used when you change the oil, or anytime in between.

It’s really easy to use. It does come with instructions on how to use it, but for best results we would recommend following what it says in your vehicle’s manual about using engine additives.

More often than not though, it’s simply a case of pouring the entire contents into the crankcase or transmission. But for power steering vehicles, you need only use one or two ounces. 

This works well as a noise reducing oil for diesel engine models.


  • Immediately silences engine noise!
  • Lubricates engine, reducing friction
  • Also helps to reduce excess heat
  • Also helps to reduce engine sludge
  • It can be used in any type of engine
  • Excellent customer ratings & reviews 


  • You may need to buy two bottles for larger engines



Sea Foam SF-16 Motor Treatment - 16 oz. , white


When we saw the customer ratings on this beauty we just had to see what all the fuss was about - and we weren’t disappointed.

After well over 15,000 individual customer ratings the average customer rating still comes in at a whopping 5 stars out of 5.

This review is for the gas and diesel treatment, but there’s also a special version for trucks and SUVs, and yet another special treatment for high mileage motors.

It comes from a very well established brand that was founded as far back as 1942.

Its main effects are two fold. It is designed to both clean and lubricate 2-stroke and 4-stroke gas engines and diesel engines. And these two functions together mean that it can really reduce any engine noise. It will also work with gas-ethanol blend oils and biodiesel blend oils.

It’s made with 100% pure petroleum and the reason it can clean up an engine so well is because it liquifies gum and varnish deposits in and around the engine parts. It will clean the injectors and the carb jets.

And a cleaner engine means you get a smoother running, longer lasting engine, and the engine will start easier too.

It also has several other benefits besides. It adds lubricity to fuels, it quotes noisy lifters, it lubricates the upper cylinders, and it even has de-icing properties.

Sea Foam also helps any fuel stored in the vehicle to resist evaporation, effectively preserving the ignition vapors, and preventing gum and varnish formation, stabilizing the fuel. 

And better yet, it will continue to work continuously for quite some time, and you won’t have to buy another bottle for a good two years or so.

And all you have to do is pour a little into the crankcase or to the fuel tank, depending on which benefits you want to get.

No wonder it’s such a prominent bestseller with the leading online retailers in the category of Carburetor & Throttle Body Cleaners. 

Retailers occasionally have deals on this particular engine additive - simply click on “Check Price” to see if there’s a deal on now.


  • Phenomenal customer ratings
  • Very effective engine cleaner
  • Really lubricates engine parts
  • Significantly reduces engine noise
  • Sustains the engine for up to 2 years
  • Boosts the engine’s performance


  • The only real issues customers have had with this product is on the delivery and packaging



Marvel Mystery Oil MM13R Mystery Oil - 32 oz.


Now, this is an engine additive that really sells well. A prominent best seller with the leading online retailers in the category of engine and oil fluid additives.

It comes from a very well established brand, founded as far back as 1923 in Chicago.

It has several benefits. It keeps engines clean and free of sludge. It lubricates the upper cylinder of the engine for smoother idling. It improves compression, extends the life of the engine, boosts the engine’s performance, and ultimately gives you more miles per gallon. And all the while it also serves to reduce excess engine noise.

It can be used in a wide range of vehicles and machines. You can use it with gas, diesel or ethanol blend fuels, and you can use it with both conventional and synthetic oils for both 2-stroke and 4-stroke engines.

It’s very easy to use. You simply replace 20% of your engine oil with this instead, and repeat this with every oil change for best results.

Or alternatively, you can add it directly to your fuel tank to improve your fuel economy. All you have to do is add 4 ounces of this engine additive to every 10 gallons of fuel.

It’s available in bottles of different sizes, including 32 ounces, or a gallon, and you can often save yourself some money by buying in bulk.


  • Excellent customer ratings & reviews
  • It keeps engines clean and free of sludge
  • It lubricates the upper cylinder of the engine
  • It extends the lifespan of the engine
  • It gives you more miles per gallon
  • It reduces excess engine noise


  • Some people have complained about the odor



Liqui Moly 20004 Hydraulic Lifter Additive 300 ml


Internal combustion engines often feature hydraulic valve lifters, or hydraulic tappets, and these can often be quite noisy.

Well this particular engine additive directly targets these hydraulic tappets and is the best oil additive for lifter noise. And it not only reduces engine noise, but it also works to prevent engine noise caused by these hydraulic tappets.

But that’s not all. It also works to clean valve bores, it boosts the lubrication properties of your oil, and it reduces general wear and tear on the engine. You can even use it in vehicles with catalytic converters or those with turbochargers.

We recommend that you use it after every oil change. It can be added to all commercially available engine oils. It’s very easy to use, all you have to do is add one 300 ml can for every 6 liters of oil.

It comes from a very well established German manufacturer that has been in the business for over 60 years. 

This is the best additive to quiet hydraulic lifters.


  • Both reduces & prevents engine noise
  • Lubricates to reduce wear and tear
  • Directly targets hydraulic tappets
  • It’s an awarding winning product
  • Excellent customer ratings & reviews


  • It can soon become expensive if you carry out frequent oil changes



Rislone Engine Treatment,Pack of 1,100QR


Here’s yet another great additive to quiet engine noise.

This product also comes from a very well established brand, in this instance one that dates back as far as 1921.

This additive both conditions and cleans your engine. It specifically targets engine noise such as a ticking lifter or chatter, and sludge buildup, reducing friction and wear. 

And as a side benefit, it also works to maximize your engine power, by making it more responsive. It does this by extending the engine’s lifespan, by lubricating and treating the various metal parts. And it has a preventative function too. It maintains oil viscosity, and it dissolves and removes any harmful deposits that may form over time.

The reason this engine noise reducer is so effective is because it’s designed to penetrate into bearing surfaces, ring grooves and piston rings where sludge is more likely to form.

It’s great value for money, costing under $10 per quart bottle. And you can save money by buying a pack of 6. 

We were also reassured to learn that it’s made right here in the good old USA.


  • Cleans and conditions your engine
  • Specifically targets engine noise
  • It lubricates various metal parts
  • Dissolves & removes harmful deposits
  • Maximizes engine performance


  • It’s not a cure for parts that need replacement

Best Additive to Quiet Engine Noise - Buying Guide

As promised, here’s your buying guide. You may also want to check our guide to the quietest electric fuel pump for your car. 

Here are a few key points to consider before you jump ahead and buy your additive.

Right Type Of Oil For Your Engine

Your first and foremost consideration should be whether the additive is designed to be used in your particular engine. For example, you can’t always use the same engine additives in a diesel engine that you would in a gas engine, and vice versa. The same goes for hydraulic engines. Though there are some exceptions

Viscosity / Thickness

As to how viscous or thick the additive should be, this comes down to the openings inside the car engine. As a general rule, thicker oil additives are best. However if the car has particularly narrow openings and tubes, you may be better off with a thinner additive in this instance. But bear in mind, the additive will not generally alter the thickness of the engine oil.

Additive Composition

What chemicals the additive is made up of determine the effects it will have on your engine and vehicle. Some chemicals have a more significant effect than others.

Zinc is a good example of an additive that really benefits your car engine. Not only will it keep the engine quiet, but it will also boost the engine’s performance.

Phosphorus is another great ingredient, and is often to be found in engine additives. It serves to reduce the general wear and tear of an engine, and consequently increase the engine’s lifespan.

Lubricating Properties

One of the ways that an engine additive can quiet an engine is by lubricating the various parts of the engine so that they move more easily without rubbing, and causing less friction.

EPA Approval / Endorsement

Sometimes a manufacturer will state that an engine additive is approved, certified or endorsed by the United States Environmental Protection Agency (EPA). And while these engine additives may well fall in line with EPA requirements, the EPA does not actually endorse any engine additives.

Mile Per Gallon Increase

As we made reference to a little earlier, many engine additives are designed to boost engine performance, and this often means achieving more miles to the gallon. Now, this doesn’t necessarily reflect how quiet the engine will run, but it sure is nice to have a more efficiently running engine, and it will save you money on fuel.

Value For Money

Unfortunately engine additives are not exactly a one-time buy. In order to keep your engine in tip-top condition, you will need to buy engine additives on a regular basis. Moreover, some engine additive manufacturers specify that you should use a whole bottle in one go.

We haven’t included the prices in our product reviews in case they change, but if you want to find out the price, and value for money, you can simply click on “Check Price” and the product page will then open up in a new tab.

Frequently Asked Questions

How can I make my engine sound quieter?

The first thing you should do if you find that your engine is too noisy is to establish why it’s being so noisy. We recommend that you take it to a garage for a quick check over. It is only when you determine what the problem is that you can know how best to treat the issue.

Sometimes all that’s needed is a change of oil or a quiet electric fuel pump. And you can boost the performance of your oil by using engine additives, such as the ones reviewed in our shortlist above. 

Sometimes the source of noise may be your tires and not your engine. Check out our guide on how to quiet cupped tires.

Does Sea Foam help with lifter noise?

Seafoam is one of the most well known engine additives, and it made a spot in our shortlist. It has several great benefits, and we’re pleased to report that one such benefit is it quiets noisy lifters.

What is the best additive to quiet engine noise?

Our favorite engine additive to quiet engine noise is our number one pick, the Dura Lube HL-41705-04 Severe Instant Quiet Motor Oil. It’s one of the very few engine additives on the market today that is specifically designed to immediately silence engine noise and transmission noise. And it’s excellent at what it does,  which is why it has attracted so many positive customer ratings and reviews.