Do Fuel Injector Cleaners and Other Gas Additives Really Work?

Stephen Fogel
March 23, 2018

Fuel additives are products that you pour into your gas tank to solve, or prevent a specific problem — and if you’ve been inside a gas station or auto parts store, you know there are a lot of them to choose from. These additives are designed to accomplish a variety of objectives. But some types are more trustworthy than others.

fuel additives

Fuel additives that typically work

Let's start with the ones that usually do what they claim, and whose performance is easy to verify:

  • Fuel stabilizers, used to keep fuel in seasonally used vehicles like boats, RVs and sports cars from decomposing and causing corrosion during long periods of storage.
  • Octane boosters, used to raise your fuel's octane rating for high-performance or racing applications.
  • Anti-gel diesel additives, used to help diesel fuel to flow better at very low temperatures.

What about fuel injector cleaners?

Other products are meant to keep your fuel injectors clean and performing at their best, free of carbon deposits. But how can you know if they’re working in your engine?

Fuel injectors have tiny valves that regulate the amount of fuel sprayed into the engine, as directed by your engine's computer. Because fuel-injected engines meter fuel very precisely, they have been able to meet increasingly stringent emissions and fuel economy standards.

Fuel injectors run at very high fuel pressures and very high temperatures, either right next to or inside of your engine's combustion chambers. In addition, most gasoline today has ethanol blended into it by law, which accelerates the formation of carbon deposits. This is a very hostile environment for a high-precision piece of equipment like a fuel injector. A small piece of carbon can affect its performance. These carbon deposits also build up on engine parts, reducing fuel economy, increasing emissions and affecting vehicle performance.

Buyer beware

The truth is, many of claims made by fuel injector cleaners haven’t been scientifically proven, and there’s no way to know if they'll work for you.

Fuel injector cleaners will note that they have been registered by the EPA, but in actuality, every fuel additive sold can make this claim. In fact, all motor vehicle fuel additives must be registered with the EPA. It's the law. What’s more, this registration has nothing to do with whether the product does what it claims. As the EPA stated in a 2011 report about fuel additives:

"EPA does require fuel additives to be ‘registered,’ but EPA does not test candidate products for engine efficiency, emissions benefits, or safety as part of the registration process. To register an additive, manufacturers must report the chemical composition along with certain technical, marketing, and health effects information. In some cases the manufacturer may be required to conduct testing or literature research to assess potential emissions health effects."

"The EPA registration process does not include a check of manufacturer product efficacy claims. In other words, EPA does not determine whether or not the fuel additive works as advertised. Registration does not represent EPA endorsement of the product."

Use Top Tier fuel instead

The good news is there’s an easy way to keep your engine clean of deposits. Vehicle manufacturers are well of the problems caused by carbon deposits. In response, the manufacturers worked with certain oil companies to put a special, high-strength additive package, with superior deposit-cleaning qualities, into their gasoline. 

Starting with a few gasoline brands, this trend has swept through the industry. It has led to the creation of Top Tier Detergent Gasoline, in which any brand meeting the Top Tier enhanced additive standards is licensed to use the term to promote its products. Many auto manufacturers have recommended the use of Top Tier Detergent Gasoline in their vehicles. 

This is a great first step toward keeping your engine clean and free of deposits, and it costs virtually nothing.

Recent AAA testing, using an independent laboratory, showed that non-Top Tier gasolines caused 19 times more engine deposits, after only 4,000 miles, than those that meet the Top Tier standards. AAA recommends that drivers use Top Tier Detergent Gasoline.

To identify which retail brands are licensed to sell Top Tier Detergent Gasoline, simply visit the Top Tier website and check the list.

Get it diagnosed by a professional

More help for fuel injectors 

If you have been using Top Tier fuel and you think that your fuel injectors aren't working properly, then it’s time to see your mechanic. If your injectors are really clogged with carbon, a physical cleaning may be in order.

To do this, your fuel injectors are removed from the engine and thoroughly cleaned. This process usually uses a very strong chemical solvent, one that the EPA would never approve for a pour-in-the-gas-tank product.

First, the injectors are soaked in the solvent with ultrasonic vibration applied. Next, the solvent is forced through the injectors at high pressure in the reverse direction of the normal fuel flow. Finally, the injectors are media blasted to remove external deposits, and the wear parts like O-rings and seals are replaced. This process should restore the performance of your injectors.

Keep your engine running smoothly

If you want to keep your engine and fuel injectors free of deposits on an ongoing basis, without pouring your money down the drain, here are some helpful tips:

  • Additives don't necessarily make any difference, so use them at your own risk with zero expectations. Advertising claims are not the same as proven results.
  • Some shops and dealers automatically add fuel additives to their maintenance services. Opting out of these when getting your vehicle serviced can save money on maintenance costs.
  • Use Top Tier Detergent Gasoline for engine cleaning and deposit prevention in everyday driving.
  • If it ain't broke, don't fix it! A properly running vehicle shouldn't need any additives.

If your car isn't running properly, have your mechanic check it out. It may or may not be a fuel system or fuel injector issue.

Stephen Fogel

About the Author

Stephen has been an automotive enthusiast since childhood, owning some of his vehicles for as long as 40 years, and has raced open-wheel formula cars. He follows and writes about the global automotive industry, with an eye on the latest vehicle technologies.

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