Do Fuel Additives Work?

As the data show, AMSOIL P.i.® is a potent fuel-injector cleaner that works after one tank of fuel.

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AMSOIL P.i.® Performance ImproverAMSOIL Upper Cylinder LubricantAMSOIL Diesel Fuel Additives
by John Baker
April 13, 2022

Store shelves are littered with additives for fuel and engine cleaning additives that claim to increase fuel economy, smooth engine operation, reduce emissions, extend engine life, maximize horsepower and more. Do fuel additives work, and does fuel injector cleaner work? We’ll take a look in this post.

Do Fuel Additives Work?

A quick internet search reveals multiple articles that claim they don’t. There must be a good reason so many people regard fuel additives with skepticism.

While most motorists expect to see the benefits promised by fuel additives immediately, it takes several tanks of treated fuel before most additives provide any noticeable performance improvement.

Having to use a fuel additive for several tanks of fuel doesn’t bode well in a society used to getting what it wants, when it wants it.

Engine Condition Affects Whether Fuel Additives Work

Here’s what often happens.

Over time, performance-robbing deposits form on your engine’s fuel injectors, valves and in the combustion chamber. Today’s injectors are highly engineered to tight tolerances, and even minute deposits interfere with the spray pattern and reduce power and fuel economy.

The problem is especially pronounced in high-pressure common-rail (HPCR) diesel engines and in direct-injection engines that locate the injectors in the combustion chamber exposed to intense heat.

Eventually, you notice a reduction in power, throttle response, fuel economy or drivability. You pick up a fuel additive at the gas station or parts store.

“Increases Fuel Economy!” it proclaims. “Outstanding,” you think as you empty the bottle into your fuel tank.

But, by the time you pull up your driveway, nothing has changed. Or again the next day after you arrive at work. “Do these fuel additives even work?” you ask yourself.

Does Fuel Injector Cleaner Work?

What went wrong when it seems your fuel injector cleaner didn’t work?

Technically, nothing. You likely bought an inexpensive fuel injector cleaner that contains minimal cleaning agents. If you continue to buy the additive and use it with every tank of fuel, maybe over time – could be weeks to months – you may experience a slight up-tick in power, fuel economy or drivability.

Then you can continue to use the additive to maintain engine performance. The fuel injector cleaner did, indeed, work and it did live up to its performance claims. It just didn’t do it quickly or dramatically enough.

Best Fuel Injector Cleaner

It takes a fuel injector cleaner formulated to the correct concentration to deliver immediate results. But most additives for fuel simply don’t contain a sufficient concentration of cleaning agents to provide immediate results.

That’s where AMSOIL is different.

AMSOIL P.i.® Performance Improver is a potent, deep-cleaning gasoline fuel injector cleaner featuring concentrated detergents that aggressively clean stubborn, power-robbing deposits from injectors, valves and combustion chambers. It reduces emissions and increases fuel economy up to 5.7%.¹

AMSOIL P.i. Also Works In GDI Engines

What’s the best fuel injector cleaner for gasoline direct-injection (GDI) engines?

In GDI engines, injectors are located inside the intense heat-and-pressure environment of the combustion chamber, making them particularly vulnerable to deposits. Extreme pressure combined with incomplete fuel combustion can lead to dramatically increased soot (particulate matter) levels.

Direct injection typically creates 30 to 40 times more soot than port fuel injectors (PFI). Even a minimal amount of injector fouling can lead to increased pollution and wear and decreased power and fuel economy.

AMSOIL P.i. is one of the best fuel additives and best fuel injector cleaners available. It removes stubborn deposits and keeps injectors functioning as they should. Testing shows P.i. restored GDI fuel injectors to a 100% flow rate after one tank of fuel.²

Rather than spend money on expensive fuel injector cleaning methods, try AMSOIL P.i. first as a relatively low-cost, highly effective option.

How About Upper-Cylinder Lubricants?

Many additives for fuel are marketed as upper-cylinder lubricants. The intense heat of combustion and limitations of the oil-control piston ring result in a lack of oil at the top of each cylinder. This can lead to ring and cylinder wear that reduces engine compression, decreasing power and performance.

Again, though, some additives don’t provide much, if any, lubricity improvement, as the chart shows. AMSOIL Upper Cylinder Lubricant, however, delivers 18% more lubricity than Lucas³ and 20% more than Sea Foam³ for better retention of horsepower and fuel economy. It also fights ethanol-related corrosion. Check out the video below for more.

Don’t Forget the Diesel Fuel Additives

For peak performance, diesel engines need a daily dose of detergent for cleaning and lubricity to protect the injectors and fuel pump while keeping the combustion chamber clean.

And don’t forget AMSOIL Quickshot® for your small engines and powersports equipment. It cleans performance-robbing deposits, stabilizes fuel during short-term storage and fights ethanol problems.

So, do fuel additives work? And does fuel injector cleaner work? Yes, if you use the right ones.

¹Based on independent testing using EPA tests: Federal Test Procedure 75 (FTP), Supplemental Federal Test Procedure (US06), and the Highway Fuel Economy Test (HFET). Average fuel mileage increase of 2.3 percent.
²ASTM D5598(M) – 2013 Buick Regal test vehicle
³Based on independent testing of AMSOIL Upper Cylinder Lubricant, Lucas Upper Cylinder Lubricant and Sea Foam Motor Treatment obtained on 02/13/2019 using the ASTM D6079 modified for use with gasoline.

by John Baker

AMSOIL Technical Writer and avid avid DIYer with 12 years in the synthetic lubricants industry, who enjoys making technical topics in the automotive, powersports and industrial markets easy to understand.

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AMSOIL P.i.® Performance ImproverAMSOIL Upper Cylinder LubricantAMSOIL Diesel Fuel Additives

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