Best Fuel Injector Cleaners: 2021’s Best Picks

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Your car’s fuel injector is arguably its most important component, as it is responsible for periodically spraying liquid fuel into the cylinder of your engine. When your fuel injector is dirty, it can become clogged, which prevents it from delivering the right amount of fuel at the proper pressure.

Also, the fuel will not burn as efficiently, which results in a loss of power and poor fuel economy. This is why it is important to keep your fuel injector clean. However, finding the right cleaner for the job can be a tough challenge.

We’ve put together this list of some of the best fuel injector cleaners out there to make your next purchase a little easier. Read on for the full review of the best models and how to go about choosing the best option for your needs and preferences.

Comparison Chart

31gBZlrrmZL. SL160
Red Line (60103) Complete SI-1 Fuel System Cleaner
Best Choice
Gumout 510013 Fuel Injector Cleaner
Best Price
41EGArltRjL. SL160
STP 78568 Complete Fuel System Cleaner
Best Mileage

Best Fuel Injector Cleaners Reviews

Red Line Complete SI-1 Fuel System Cleaner


Starting off, we have an extremely comprehensive solution to fuel injector cleaning. The Complete Fuel System Cleaner from Red Line, as the name suggests, is designed to provide you with a full system clean for your fuel injectors so that you can rest assured knowing that no stray dirt or debris is lingering in your car’s fuel injector.


Red Line states that this concentrated cleaner was designed to exceed your expectations, but you will, of course, have to prove that claim for yourself. The Complete SI-1 Fuel System Cleaner is meant as a treatment for cleaning away dirt and debris and preventing any further corrosion from occurring within the fuel injector and other fuel systems.

This fuel additive not only cleans your car’s fuel injector but also its carburetors, combustion chamber deposits, and valves. It does this with a potent, concentrated blend of high-temperature and low-temperature detergents. This provides the comprehensive internal cleaning that many cars these days desperately need and that many car owners neglect doing.

While you may think that the amount of product that you receive when purchasing a bottle of Red Line Fuel System Cleaner is insufficient – since you only get 15 ounces – you’d be surprised. This is an extremely efficient fuel-burning formula, and it is a gas treatment that enhances the stability of the gasoline that goes into your car while also reducing the accumulation of varnish formation and gum.

The Good

This product is designed as a one-use-only product. You are supposed to use one bottle per tank of fuel to make the treatment and cleaning as effective as possible. The additive was designed to work at almost 100% efficiency in one treatment, meaning you don’t have to constantly add a cleaning solution to your car.

This is also great for people who are not savvy when it comes to automobiles and don’t want to have to stress about whether they’re doing the right thing or not. Just pop a bottle in and you’ll be good to go, knowing that your car is getting the deep cleaning it deserves.

The Bad

Some customers have reported that the bottle this product comes in can sometimes be leaky and that there is a very strong smell of fumes. Be sure to wear protective gloves and some kind of mask when pouring this solution into your car.


  • Prevents corrosion
  • Provides comprehensive cleaning
  • Efficient fuel burn
  • Easy to use
  • Enhances gasoline stability


  • Powerful fumes when opening the bottle
  • Bottle has been known to leak


Royal Purple Max-Clean Fuel System Cleaner & Stabilizer

The Max-Clean cleaning solution from Royal Purple represents a state-of-the-art product in the fuel injector and system cleaning industry. It contains some of the most potent chemicals and powerful technologies that help keep the inner workings of your beloved vehicle clean and working at maximum operational efficiency. The only downside is its inflated price tag, but it is worth it.


Royal Purple’s Max-Clean Fuel System Cleaner and Stabilizer is able to deeply penetrate your fuel injectors, intake valves, carburetors, and combustion chambers to cleanse them and restore your fuel economy while also reducing your emissions. With its extreme versatility, this cleaning solution is safe for use in both gas and diesel engines, as well as all ethanol blends or biofuels.

If you are looking for a cleaning solution that will not only give the inner workings of your car the cleaning that it needs but also one that will improve your car’s fuel economy and efficiency, then this may just be the product for you. Max-Clean by Royal Purple is able to improve your fuel economy by an average of 3.2%, as well as your horsepower by an average of 2.6%.

It will also help reduce nitrogen oxide, hydrocarbon, and carbon monoxide emissions by quite a hefty amount, making your car more environmentally friendly overall. With this product, you will also be able to prevent rough idling, stalling, hesitation, and the premature fouling of your spark plugs, while simultaneously stabilizing fuel during storage and off-seasons.

The Good

Like we mentioned earlier, one of the best features of Max-Clean is that it is able to improve your car’s fuel economy. While 3.2% might not seem like much, it can make quite the difference in the long run and save you some dollars.

You’ll also be reducing your carbon footprint when you use this product, which is great for folks who are looking to be more eco-friendly.

The Bad

Unfortunately, like most fuel injector cleaning solutions, the effects of Max-Clean tend to fade away quite quickly. This means that you might have to purchase a few more bottles of the stuff, but one treatment should be enough.

Read our in-depth review of Royal Purple Max-Clean Fuel System Cleaner & Stabilizer.


  • Improves fuel economy
  • Reduces fuel emissions
  • Prevents rough idling, stalling, & hesitation
  • Stabilizes fuel in storage
  • Inhibits corrosion & oxidation


  • Effects wear off after one tank


STP Complete Fuel System Cleaner


This is another great product for anyone out there who is trying to make each gallon of gas take them a little bit further. By keeping your car’s insides clean, the Complete Fuel System Cleaner from STP is able to help your gas last longer and be more efficient, which results in less money spent on gas and more money in your pocket.


It’s no secret that a dirt fuel system is one of the most common causes of performance loss in your vehicle, as well as rough idling and hard starting. STP offers a revolutionary fuel system cleaner in the form of this product, which has been scientifically engineered to clean your entire fuel system thoroughly and to protect it from loss of performance.

It does this with just a single treatment, after which your car should be performing at peak capacity and efficiency. The fuel additives in the STP Complete Fuel System Cleaner helps you save money on gas by cleaning out your entire fuel system and removing any deposits of dirt and debris that may have accumulated over the years.

All STP cleaners are made using jet fuel and are safe for all gasoline engines. Their products are fantastic if you are looking to get the most power possible out of your vehicle, regardless of whether you’re operating a gasoline or diesel engine. The brand has a range of premium quality products that will further maintain and improve the performance of your car for good.

All STP products are specially formulated and are tested extensively to demonstrate their ability. They are designed to help keep your vehicle running smoother and stronger for those long drives.

The Good

The most powerful benefit that the Complete Fuel System Cleaner provides is that it saves gas by keeping your fuel intake system clean. Naturally, this results in less money spent on buying gas, leaving you with more money in your pocket to spend on other things. It also helps prevent corrosion.

The Bad

The only major downside to this product is that you don’t get much fluid in one bottle, so this might not be the most budget-friendly solution to cleaning your fuel intake system.


  • Better gas efficiency
  • Restores car performance
  • Inhibits corrosion
  • Works with cap-less tanks
  • Removes deposits from fuel system


  • Not a lot of product in one bottle


Liqui Moly Jectron Gasoline Fuel Injection Cleaner

This is a 300ml cleaner that is able to clean out your contaminated fuel injection system, remove carbon deposits from fuel pipes, and reduce the buildup of dirt and debris. It is designed to ensure that your car does not experience starting problems, has smoother idling, and experiences a smoother throttling. This makes it great for those trying to improve their car’s performance.


For the best results from this fuel cleaner, you should add it to your tank when it is at ⅛ of its maximum capacity. You should also add the entire bottle to ensure thorough cleaning. By the time you have refilled your tank, you should notice an improvement in the performance of your car’s engine.

You will mostly notice the improvement when driving on highways than when traveling at high speeds. The cleaner is able to aid in the cooling of the engine, which reduces the chance of any problems brought on by the overheating of the engine.

Any car owner would find this fuel injector cleaner appropriate since it can also be used by any synthetic oil that works well with cleaners in terms of delivering the services that the cleaner is supposed to. This product is recommended for those who own cars that hold 5W-20 oil.

When using this cleaner for the first time, you will notice that your car takes much less time to start up, as the engine will be operating more efficiently. You should also notice that, as you let go of the clutch, your car will pull away more smoothly, unlike the rapid jolting that you may have grown accustomed to.

The Good

The great thing about the Liqui Moly Jectron Fuel Injector Cleaner is that it helps make your car run more smoothly. We often grow used to our cars jolting forward when we pull away because of how dirty the fuel injector has become, but once you start using this cleaner, you’re never going to want to feel anything other than smooth gliding as you pull away.

The Bad

You only get 300ml of liquid from this product, which isn’t much at all. If you are looking for more cleaning solution for your money, you may want to try one of the other products on this list.


  • Eliminates starting problems
  • Provides smoother idling
  • Gliding pull-aways
  • Cleaner combustion
  • Better throttle response


  • Very little product in one bottle


Gumout 510013 Fuel Injector Cleaner

Finally, we have the Gumout Fuel Injector Cleaner, which is designed to treat cars that have high mileage. This is one of the most potent injector cleaners out there because it is designed to clean out the inner workings of cars that have not had any special treatment in a long, long time. If your car needs a good, thorough cleaning, this is the product for you.


The Gumout Fuel Injector Cleaner is meant to clean out carbon deposits from the engines of cars that have more than 75,000 miles under their belt. This means that, if you are looking to clean out your brand new car, you’d be better off with a milder product – this one could be a bit of overkill.

This cleaner also prevents the future buildup of carbon on the port and indirect fuel injectors, as well as intake valves and other ports. It can also be used as a kind of preventative measure for those who don’t want to have to clean out their cars too often.

Another benefit that this product has is its ability to improve both the fuel economy and performance of your vehicle, allowing you to go further on less gas. This results in savings, as you won’t be spending as much money when you stop to fill up your tank.

The Good

Not only does this product save you money, but it also reduces your car’s emissions, making it a more environmentally friendly vehicle. It is safe for oxygen sensors and is also safe for use in vehicles that have been turbocharged and supercharged.

The Bad

This product probably won’t be very effective on new cars. It is designed to work on cars with a lot of miles on them, so if that isn’t your car, you should look at some of the other products on this list.


  • Great for cars with 75,000+ miles
  • Prevents future buildup of carbon
  • Improves performance
  • Greater fuel economy
  • Reduced emissions


  • Not as effective on newer cars


Buyer’s Guide: What to Look for When Buying a Fuel Injector Cleaner?

Before purchasing fuel injector cleaners for your vehicle, there are a few issues you need to keep in mind. These factors are outlined below to help you make the best purchasing decision for your needs.

Types of Fuel Injector Cleaners

There are various types of fuel injector cleaners that you can use to keep your car’s engine clean. The most popular are the liquid versions that are poured into your tank – all of the products mentioned on this list are of this type.

Then, there are rail-induced cleaners, which are used by repair shops and most car dealerships. Finally, there is the ultrasonic injector cleaning method, which involves placing your car in an ultrasonic bath for about an hour. Needless to say, this is not a method that you’ll be trying at home.

Product Benefits

Fuel injector cleaners are a must-have for any car owner who is dedicated to keeping their car in the best shape possible. They should be used on a regular basis to ensure that the engine is clean and that your car is operating as efficiently as possible. This will also help prevent you from running into any problems later down the line.

Main Features

As you can tell, different fuel injector cleaners offer different features to your car. Some are able to completely remove dirt and debris from the engine, which results in a comprehensive improvement in performance, while others will help reduce your car’s emissions and make it more environmentally friendly.

It is important that you take note of these features when deciding on a cleaner to purchase, as the features that one offers might not be the ones that you need.

Compatibility With Your Car

Most liquid fuel injector cleaners will be compatible with any type of car, but some of them have specific requirements. If you drive a gasoline car, then you will want to ensure that you are using a fuel injector cleaner that can work with gasoline and not one that is only meant for diesel.

If your car is turbocharged or supercharged, then you will need to purchase a cleaner that can work with those specs, as any other might result in some serious damage when you start up and try to drive around.


Many liquid fuel injector cleaners are quite affordable, and most of them shouldn’t set you back more than $40. If you are looking for a general clean and don’t want any special features, then you should have no problem purchasing one of the cheaper options. The more expensive cleaners usually serve specialized purposes.

Frequently Asked Questions on Fuel Injector Cleaners

What is the purpose of a fuel injector cleaner?

Fuel injector cleaners aid in the prevention of accumulated hydrocarbons and other deposits that are harmful to your car. It is also believed that they can help maintain the health of your fuel injectors, and many major fuel brands today will already contain some form of cleaner in them.

The injectors dissolve solids that have built up in the injection system and also prevent these solids from forming again over time.

Where do you put fuel injector cleaner?

You should pour a suitable amount of fuel injector cleaner into your fuel filler when your tank is almost empty. Once you have done that, you should top off your tank with your usual fuel.

How long does it take for fuel injector cleaner to work?

It will usually take about one full tank of fuel for you to notice the effects of the fuel injector cleaner. If it does not, then you should run through another tank at the concentration that is recommended by the brand of cleaner that you are using.

The effects may take a few days to show, but if you find that the cleaner is still not producing the effects that you want it to, then you may want to consider bringing your car in to a specialist who can identify any other problems that may be causing your car to operate at less than maximum efficiency and performance.

How do you know if you need a fuel injector cleaner?

There are several common symptoms that your car will display that lets you know it’s time for a fuel injector cleaner. The first and most common is a rough idle or engine stall, which happens when your car is getting an insufficient or uneven supply of fuel.

Your engine will also feel as though it is vibrating because the corresponding cylinder will not be able to fire. This means that, while you are driving, the engine will hiccup as it attempts to complete each cycle without fuel.

If you are smelling fuel, then you have gasoline that is not being burned because your fuel injector is faulty.

What is the difference between a fuel injector cleaner and a fuel system cleaner?

Where a fuel injector cleaner would clean only your car’s fuel injector, a fuel system cleaner will clean the fuel injector, the valves, and other important components of your car’s engine. The latter is good for general maintenance, while the former should be used when you’re having injector-specific problems.


There you have it, folks – a complete review of some of the best fuel injector cleaners out there. We hope that this article has been useful and that you’ll be able to go out there and buy the right injector cleaning product for you.

1 thought on “Best Fuel Injector Cleaners: 2021’s Best Picks”

  1. Pingback: How Often to Use Fuel Injector Cleaner? - TRE Racing Engines

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