After a while, your car might not accelerate as quickly as it once did, the engine may not run as smoothly as you remember, or the fuel economy may dip—but everything else may otherwise work fine. If that happens, it might be time to treat your engine to a fuel injector cleaning. Your engine has a lot of moving parts and if there’s gunk and grime buildup inside, it has to work even harder to get the job done. A clean engine is a more efficient engine (and also a more powerful one), so a fuel injector cleaning is an important part of maintaining your car.

While you can always visit a mechanic to get this service done, drivers can save a bunch of money by doing it themselves. Fuel injector cleaners are probably the easiest engine additive to use and drivers can do it even if they have no tools or a garage. These products allow you to simply apply a fuel injector additive to your fuel tank, cleaning out the inner workings of your engine’s fuel system and reducing the chance that you’ll need to perform costly maintenance work sometime down the road.

Drivers looking for fuel injector cleaners are spoiled by a huge amount of options, but we’ve made a list of the best fuel injector cleaners on the market today to make your buying decision easier. These are among the most popular and highest rated fuel injector cleaners, so you can buy these products knowing that they have been tested and approved by other consumers just like you.

For more information on the best fuel injector cleaners, refer to our table of contents.

1. Editor's Pick: Chevron Techron Concentrate Plus Fuel System Cleaner

chevron techron concentrate plus fuel system cleaner

This is one of the most popular fuel injector cleaners available in today’s market and it comes from a well-known brand. In fact, it’s often recommended by automakers as a solution for cleaning the fuel injection system. It works on lighter vehicles of all types, carbureted or fuel injected engines. It will also work on your two-stroke motorcycles, just be sure to put lower amounts in the tank—as much as it says on the instructions on the bottle.

According to the company, it will clean and restore the entire fuel system, including the fuel injectors, intake valves, and combustion chambers. Recommended usage is every 3,000 miles for cars and trucks, or right before an oil change. For engines that don’t have a counter, like your lawnmower, use it as needed.

2. Red Line Complete SI-1 Fuel System Cleaner (60103)

red line complete si-1 fuel system cleaner

Most of the fuel injector cleaners have the same basic chemicals, but Red Line has patented a formula that puts it in front of the competitors. Thanks to that, the Complete SI-1 Fuel Cleaner not only cleans your injectors and the carbon build up in the engine, but also lubricates the upper part of the cylinder and reduces the need for high octane gasoline.

In other words, it will not only clean your engine, but it will make sure that it’s lubricated properly and that it works fine with lower quality gasoline. The company recommends using one bottle per tank of gas. It can be used on all kinds of vehicles, including cars, trucks, off-road vehicles, motorcycles, marine engines, etc.

You can also stock up if you plan on using this on a regular basis, as it’s available in a two-pack, six-pack, and a dozen.

3. Royal Purple Max-Clean Fuel System Cleaner and Stabilizer (11722)

royal purple fuel injector cleaner

Another well-known brand in the automotive industry, Royal Purple offers this Max-Clean Fuel System Cleaner and Stabilizer. It’s a bit more expensive compared to other recommendations on our list, but the price is worth it if you want a clean engine. It will reduce the emissions of your vehicle, helping it run smoothly and even improve the power and mileage.

This recommendation also stabilizes the fuel when you don’t drive your car for longer periods of time. One can of this fuel injector cleaner is to be used on 20 gallons of fuel. It works on any vehicle with a gasoline or diesel engine, 4-stroke or 2-stroke. The company claims you can expect to see an average fuel economy improvement of 3.2 percent and even a horsepower gain of 2.6 percent on average.

4. Liqui Moly Jectron Fuel Injection Cleaner

liqui moly jectron gasoline fuel injection cleaner

Here’s a recommendation for a very powerful additive for cleaning fuel injectors and carbon build up, especially for cars with older engines. It’s one of the fastest solutions on the market, with improvements being seen after only 1,000 miles or one tank of fuel. And since it comes from Liqui Moly, it was tested by the strict TUV (Technical Inspection Association) in Germany, so it’s one of the safest fuel injector cleaner products.

The company says that it will also not damage oxygen sensors or catalytic converters, and one bottle is good for one tank of fuel. One downside is that it can only be used on gasoline engines. Liqui moly claims you’ll get smoother idling, better throttle response, and cleaner combustion by using its Jectron Fuel Injection Cleaner. It’ll also work to help eliminate starting problems, hesitation and stalling.

5. Sea Foam Motor Treatment (SF-16)

Sea Foam Fuel Injector cleaner

Another popular option, Sea Foam’s Motor Treatment can be used on a variety of different engine types, including gasoline and diesel motors. Designed to clean away very heavy carbon build ups, it will also clean your fuel system and lubricate it so it will last longer. Ideal for older engines with a lot of deposits inside, you can also use this in conjunction with other Sea Foam products to eliminate all those deposits from your engine.

The company says this motor treatment can even work to stabilize stored fuel for up to two years by resisting evaporation, preserving ignition vapors, and preventing the formation of gum and varnish. This solution only contains petroleum-based ingredients, which means no harsh detergents or abrasive chemicals that could potentially harm your engine.

6. Lucas Oil Deep Clean Fuel System Cleaner (10512)

lucas oil deep clean fuel system cleaner

If you’re looking for one of the best treatments for carbon build up, consider Lucas Oil’s Deep Clean Fuel System Cleaner. You’ve likely heard of the brand if you’ve walked the aisles of your local auto parts store, as it is one of t he most well-known brands when it comes to automotive lubrication products. It’s very successful at treating every metallic surface inside the engine and cleaning it of deposits, as well as treating your fuel system.

As a result, using this can improve the performance and fuel economy of your car, as well as reducing NOx emissions. If you’re experiencing knocking and pinging with your engine, this is also worth a shot to try to eliminate those issues. The only major drawback with this solution is that it can only be used in gasoline engines.

7. STP Ultra 5-in-1 Fuel System Cleaner and Stabilizer

 STP Fuel System Cleaner and Stabilizer, Advanced Synthetic Technology

Another brand with a great reputation in the industry, STP offers this advanced synthetic fuel system cleaner and stabilizer. Not only will it clean your fuel system, it’ll also work to stabilize the fuel and prevent rust inside its metallic components. The company says this formula boasts three times the amount of detergents compared to other products, helping it remove 61 percent of intake valve deposits and restore the injector to 95 percent of its original performance.

Use this on a full tank of fuel (around 20 gallons) and you should experience some noticeable results, including lower emissions and better fuel economy. It’ll also work to reduce friction by lubricating engine parts, potentially improving performance. It’s compatible with cap-less gas systems and is safe to use on modern gasoline engines with turbochargers, direct injection, and even hybrid vehicles.

8. STA-BIL 360 Protection Ethanol Treatment and Fuel Stabilizer

sta-bil 360 protection ethanol treatment and fuel stabilizer

If you’re running ethanol-blended fuels in your engine, take a look at STA-BIL’s 360 Protection Ethanol Treatment and Fuel Stabilizer. It’s one of the most popular ethanol treatments out there, designed to prevent ethanol fuel-related damage to your vehicle. Like many other cleaners, it claims to increase engine power and efficiency, while working to prevent corrosion.

This recommendation works with gasoline and diesel engines, but ideally on ethanol-blended fuels. A 10-ounce bottle can be used on up to 50 gallons of fuel, so one bottle can go a long way. For those storing fuel for a long period of time, this product can work to keep that fuel fresh for up to 12 months.

9. Gumout Fuel Injector Cleaner (510019)

gumout fuel injector cleaner

Hesitant to spend a lot of money to see if fuel injector cleaner can really improve the performance of your engine? Here’s an affordable option you can use to give it a try, designed to remove carbon deposits from key engine parts. It’ll do a good job at restoring your fuel injectors to their previous glory, although it won’t be as effective as other recommendations on our list. It will however, still work to prevent future carbon build up on your fuel injectors, intake valves, and ports.

Safe to use on engines with forced induction, this solution is also oxygen sensor safe and should work to reduce emissions while slightly improving fuel economy and performance. If you’re on a budget, this is what we would recommend and if you’re happy with the results, you can continue sticking with it.

Everything You Need to Know About Fuel Injector Cleaners

four cylinder engine bay

Photo credit: Banglens /

Taking care of a car or truck engine is a task that we almost always assign to our mechanics, which is expected—you can’t really do much on your engine nowadays, besides checking the oil and coolant levels. However, going to a mechanic can be very expensive, even if the problem you have often requires a simple solution.

One of the most common problems with any fuel injected engine is that the injectors that bring the fuel to the combustion chamber can get clogged up. If you think about it, these are one of the vital parts of the engine—no fuel in the chamber means no combustion and consequently a car that will lose its power, have worse fuel economy, and increased emissions.

If you’ve never experienced your engine losing power even if it was regularly maintained, you are one of the lucky few. Clogged up fuel injectors are so common that every auto parts shop has dozens of different so-called “fuel injector cleaners” that purportedly can clean your entire fuel system and make your engine work like new again. That is if it doesn’t have other problems already.

Here, we’ll talk about everything you need to know about fuel injector cleaners and we try to answer every question you have, like why they are needed in the first place, how to use them, should you use them yourself, or go to a mechanic, and so on.

How do fuel injectors work?

Fuel injectors are one of the most important engine parts that are used to introduce fuel to the combustion chamber, where it is mixed with air and then combusted to create power. The injector receives the fuel from a high-pressure fuel pump and thanks to a very small nozzle, atomizes the fuel in very small particles so it can mix with air quickly.

The best analogy we can think of is a deodorant—a bottle already under pressure that has a small nozzle that atomizes the liquid into very small particles. The fuel injector works much in the same way, with the only difference being that here the nozzle is even smaller and the injected fuel is almost misty in appearance. Newer injectors for direct injection engines even have several nozzles on the tip to help for a better air-fuel mixture.

This is the way that every new internal combustion engine gets the fuel into the chamber, regardless if it’s a gasoline or diesel burner. The process is controlled by the ECU (the car’s computer), so the injector will always supply the fuel right when the engine needs it. Timing is very important, as injecting fuel too early or too late can cause the engine not to work as expected or even damage it.

Considering the injector is a very delicate part, with very small canals and constantly under high pressure, it needs almost ideal working conditions, like extremely clean fuel and in the case of direct injection systems, a clean nozzle tip and a clean combustion chamber.

How are fuel injectors getting clogged up?

Expectedly, the gasoline and diesel fuels that we put in our cars are never as clean as it should be. Apart from small deposits, the fuel that we get today has small amounts of water and some octane-boosting ingredients.

All of these things can have detrimental effects on the fuel injectors, but the number-one enemy is definitely carbon buildup. This is something that happens to every engine with time—during the process of combustion, the majority of the carbon leaves the engine through the exhaust system, but some of it stays in the combustion chamber and in time it can block the passages of fuel and air-fuel mixture. Add to that the possibility of the injector rusting from the water in the fuel and some byproducts from the octane-boosting Ethanol that is being widely used today, and with that your car can start losing power and consume more fuel in no time.

This is why keeping your fuel injectors clean is important—you not only lose power, but your fuel economy will fall off too. Clean injectors can save you money!

What does a fuel injector cleaner do?

Fuel injector cleaners are additives that are meant to clean all those deposits in the injector as well as in the combustion chamber and help your engine work in optimal conditions, with the right air-fuel mixture. Think of them as detergents for your fuel system.

These cleaners can clean the inside of your injector, but also the carbon buildup in the combustion chamber, behind the intake valve, around the spark plug, etc. All of them have active ingredients that help dissolve the deposits into much smaller pieces and then the engine itself ejects them through the exhaust system.

How do fuel injector cleaners work?

Fuel injector cleaners are a mixture of complex chemicals, most of them solvents that can easily clean deposits. The main cleansing agent of these additives is a chemical called PEA or polyetheramine, which is a nitrogen-based detergent that is great at dissolving carbon deposits. In addition to that, PEA is very resistant to high temperatures, which makes it great for cleaning the fuel injector as well as deposits in the combustion chamber, where the temperature can go up to 1200-degrees F.

Some cleaners contain other chemicals that the manufacturers claim it makes them superior to others, but scientific studies have shown that polyetheramine is best at cleaning carbon build up and you should always look for additives that contain this chemical.

What to look for in a fuel injector cleaner?

Always look for a fuel injection cleaner that contains the detergent Polyetheramine (PEA), as it is the strongest cleaning agent. Some of the cleaners will have Polyisobutene (PIB), that helps remove water from the fuel and Polyisobutylene amine (PIBA), which is also a cleaning agent, but not as strong as Polyetheramine. Older fuel injector cleaners even have alcohol in them for water removal, but they can damage parts of the fuel system and are best to be avoided.

When do I use fuel injector cleaner?

These cleaners are the easiest to use among any other engine additives on the market. They should be poured into an almost empty tank of fuel just before you fill up at the gas station and then the tank should be emptied by leaving the engine to idle or by driving the car.

This means that they don’t work right away—you need to drive several hundred miles before you can feel the difference. Anyway, always read the instructions on the bottle – some bottles of cleaner are for only a small amount of fuel so maybe you’ll need more than one for a full tank.

If your car was not cleaned for a long time and it has a lot of carbon deposits, one full tank of gasoline or diesel and a bottle of fuel injector cleaner might not be enough to effectively clean the injectors and the combustion chamber. When that’s the case, simply put another bottle of additive in an almost empty tank of gas and empty it by driving.

How often should I use fuel injector cleaners?

There is a difference in opinion on this topic. Some mechanics will advise you to use a fuel injector cleaner every year, or every 12,000 to 15,000 miles, before the oil change. Additive manufacturers will even instruct you to use it every 3,000 to 5,000 miles. These are not rules. We would advise against using these additives on new engines, as in that circumstances they can even help build carbon build up, which was scientifically proven in some research.

Our advice is to use fuel injector cleaners on older engines before an oil change, as well as engines that are often used in cold climate and driven on shorter distances or in congested stop and go traffic. In these situations, carbon builds up much faster and using a fuel injector cleaner will help in maintaining the optimal working conditions of your engine.

Using a higher quality gasoline or diesel fuel will also help against clogging up of the injectors and less carbon build up, so be sure that your car always gets the best one.

How will I know that my engine needs a fuel injector cleaner?

Engine with a lot of carbon build up and clogged injectors will start losing power, begin to consume more fuel, rattle at idle and have ignition problems. However, all those symptoms can be due to other parts of the engine, so be sure to always maintain your car routinely by regular oil, oil filter and air filter changes as well as spark plugs in the case of gasoline engines.

What can I expect after a fuel injector cleaner treatment?

You can expect several improvements on your engine after treating it with a fuel engine cleaner, but these results won’t happen immediately — you often have to drive a few hundred miles for it to work. Improvements include regaining power and enhanced throttle response, better fuel economy and fewer vibrations at idle. For best results though, it’s best that you check your spark plugs and air filter as well, as they can also help your engine run better.

What type of fuel injector cleaners are there?

There are several types of fuel injector cleaners out there. The basic ones will only clean the fuel system and the carbon build up inside the combustion chamber. However, there are cleaners that will also stabilize the fuel or even boost the octane value to help the engine run smoothly even on lower quality gasoline.

Some of them will even have lubricants that can help maintaining the fuel system of your car for longer periods of time. You can recognize all these products right away – they will either have “3 in 1” or even “5 in 1” description on the package. Read thoroughly on the benefits of every single one before buying.

How to Use Fuel Injector Cleaners

Keeping your fuel injectors clean play a huge role in how efficiently your car’s engine is running. Using fuel injector cleaners is an easy way to make sure your car is operating at its peak and also getting better fuel efficiency.

Using fuel injector cleaners is a pretty simple task and anyone can do it—there is no need to go to a mechanic. Before you begin, it’s important to use a fuel injector cleaner on a close to empty gas tank just before you’re about to fill up at a gas station.

  1. Buy the right fuel injector cleaner for your engine: All fuel injector cleaners are not created equally. Most of them will work on any type of fuel, but there are some that will work only on gasoline, diesel, or ethanol blends. Also, you should check if it works with turbo engines, if you have one, or with catalytic converters. Read the instructions on every package thoroughly, so you can be sure that you’ll buy the right one for your engine type.
  2. Check the instructions for the right amount of fuel injector cleaner you need: The instructions will help with measuring the right quantity you need for the size of your tank as well. Almost always, one bottle of a fuel injector cleaner is enough for one tank, but if you have larger or smaller than the average fuel tank, you may need to put more or less of the additive.
  3. Be sure that the fuel level in your car is low: Fuel injector cleaners can work even if you put them inside a full tank of fuel, but it’s best to put them inside an empty tank, so they will mix with the fuel better.
  4. Remove the fuel cap: Remove the fuel cap, as every cleaner should be mixed with gas.
  5. Pour the fuel injector cleaner into the fuel tank: Open the bottle and pour the fuel injector cleaner. Use the funnel if one is provided with the bottle so nothing spills out. Some bottles have additional measuring devices on them (attached to the bottle) – be sure to fill them with the right amount of cleaner before pouring it into the tank.
  6.  Refill your tank with fuel: After pouring the fuel injector cleaner, you should refill your car with gasoline, diesel or any type of fuel that your car uses. That’s why it’s ideal you are at a gas station while doing these steps. Dispose of the empty bottle responsibly.
  7. Empty the fuel tank by driving your car: This is self-explanatory, but there are some things to consider if you want the best cleaning.
    -It’s best to drive your car at the highway or at higher speeds. In doing this, the pressure in the fuel system will be higher, which can help the cleaner remove the deposits easily. This will also help in cleaning the carbon deposits inside the combustion chamber and eject them through the exhaust.
    -Use higher engine rpms. You can do this even when the car is stationary, or when driving. In other words, don’t hesitate to press that gas pedal, as it will help in better cleaning.
  8. Repeat steps 1 to 7 if needed: One bottle of fuel injector cleaner usually does the trick if your engine has deposits inside or some of the injectors is stuck. However, if the engine is still not working as normal, you can repeat steps 1 to 7. These additives don’t have adverse effects on the engine and using them more than one time is not a problem.


Recent Updates:

November 15, 2021: Removed unavailable Marvel Mystery Oil product. Updated links.

October 13, 2021: Added additional product links.

August 20, 2021: Promoted Product added (Hot Shot’s Secret Gasoline Extreme)

March 19, 2021: Updated the description for many of the product recommendations for clarity, updated images to reflect packaging changes on several products.

January 27, 2021: Updated with a new top recommendation.

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Q & A

Should I use fuel injector cleaners on a carbureted engine?
Carburetors can also get clogged up, even though not as quickly as injectors. That said, a fuel injector cleaner can be used not only to clean up the carburetor but also to clean carbon deposits inside the engine. We definitely recommend using one if you have an older engine.
Can I use the same fuel injector cleaner on a gasoline and diesel engine?
You should always buy fuel injector cleaners that are specified for the fuel you use in your vehicle. Both of them have similar cleaning characteristics, but they also have some additional additives that will only help the type of fuel they’re intended for. That said, most of the products can work on all type of fuels—gasoline, diesel, biodiesel, or even Ethanol blends.
Can these additives repair a bad fuel injector?
If your mechanic told you that you have a bad fuel injector, these cleaners won’t help. You should change the injector with a new one or if it’s possible, repair it at a professional.
Should I go to a professional to clean my injectors?
In most circumstances, only pouring a fuel injection additive in your gas tank can help your car drive better. However, if the injectors in your engine are very clogged up and there is a lot of carbon build up, you might want to visit a mechanic. They have additional cleaning techniques which require removing the injector and cleaning it, as well as opening the engine to physically and chemically remove the carbon build up. Even though there are some kits online that you can use to do these things yourself, we suggest against doing it, as modern engines have a lot of sensitive parts that you must remove before cleaning.
Can a fuel injector cleaner damage my engine?
All fuel additives from reputable manufacturers are tested on a variety of engines and fuel types, so it is highly unlikely that they will damage your engine in one way or another.