Type to search

Sometimes your car feels like it isn’t running like it should, so you turn to fuel additives. But do these products actually work?

Putting More Than Fuel in the Tank

Woman putting gas in her car
Woman putting gas in her car

After driving a car for thousands of miles over the course of some years, your car may not feel as peppy or efficient as it once had. The fuel system is one place to point to when contemplating this dip in performance. Fuel systems gradually corrode, suffer from carbon build up, or encounter other gunk making it harder for the engine to get the fuel it needs.

In come the fuel additives that say they’ll save the day. These products are advertised as an effective fuel system cleaning tool and claim to help your vehicle achieve better fuel economy just by dumping in the additive while filling up at the pump. While that sounds well and good, is it actually true? Or are they peddling snake oil for car owners? Plus, are all of these fuel additives the same? We’ll answer those questions and more so that you’re better informed on what you should (or even shouldn’t) be putting in your fuel tank.

What are Fuel Additives? 

Shell V-Power NiTRO+
Shell V-Power NiTRO+

Fuel additives are formulated compounds that are added to fuel in order to enhance the quality of the fuel, aid in fuel efficiency, and breakdown any unwanted build up. Major gas stations already provide some form of fuel additive right at the pump. For instance, Shell adds an additive they call Shell V-Power NiTRO+ to their premium gasoline. Shell states that this additive helps defend the engine from carbon deposits (otherwise known as gunk), corrosion throughout the fuel system, metal component wear, and reduces friction of moving parts that feature gasoline interaction like the cylinder heads.

While these fuel additives from the pump are a nice addition to your purchase, sometimes they may not be enough or they may not target a key area affecting your vehicle. That’s where the off-the-shelf fuel additives come in. Each of these store-bought fuel additives serve a different purpose when it comes to the care of your vehicle through its fuel. Some are marketed for better performance, others help keep a high-mileage vehicle chugging along, and there are some that seem to state they do it all.

Types of Fuel Additives

Off-the-shelf fuel additives come in a number of different types that each serve a different purpose when added to your fuel tank. Some of these different fuel additives are also specific to diesel fuel and shouldn’t be added to gasoline powered cars as they aren’t meant for that form of fuel. So, which fuel additives do you need if any at all? Here’s a list of the different ones you may encounter.

Fuel System Cleaner

Fuel System Cleaner - stp.com
Fuel System Cleaner - stp.com

Fuel system cleaners are the most common fuel additives used in cars. They help break down gunk throughout your fuel system, prevent more deposits from forming in the system, and create a better fuel delivery environment. Some of these fuel system cleaners also act as corrosion blockers. Corrosion within a fuel system can result from high levels of ethanol use over time, but it isn’t very common to have substantial rust in a fuel system.

Fuel system cleaners aren’t going to be a one-time use kind of product and will only show results after regular use. After regular use, your car may see marginal fuel economy improvement if it had degraded over the years. It isn’t going to wow you with a substantial miles-per-gallon increase, but it should keep your mind at ease that your system is being kept clean and protected. A clean fuel system on an older car can mean a longer life and potentially fewer mechanical headaches to worry about.

Fuel Injector Cleaner

Fuel Injection Cleaner - pepboys.com
Fuel Injection Cleaner - pepboys.com

Fuel injector cleaner is a specific variant of the fuel system cleaner. You should be looking at this fuel additive if you do a lot of short trips every day rather than longer highway trips. These shorter commutes don’t let the engine get hot enough to keep itself clean and leads to carbon build up that accumulates on the fuel injectors. Carbon build up on your fuel injectors can impact your fuel economy, so getting them cleaned up can improve your fuel consumption. Adding a fuel injector cleaner additive will alleviate this build up through the fuel and work to prevent it from happening again.

Fuel Stabilizer

Fuel Stabilizer - amazon.com
Fuel Stabilizer - amazon.com

Gas loses some of its luster after having sat untouched in the tank after about 30 days. Having that old gas can lead to performance issues once that car is started up again, so adding a fuel stabilizer can be helpful. Fuel stabilizers can be added to the fuel before it gets too old and help stop that fuel from getting old. This is only really needed if you have a summer car that you put away for those winter months.

Octane Booster

Octane Booster - lucasoilcenter.com
Octane Booster - lucasoilcenter.com

Got an old ‘70s muscle car with an original engine that craved leaded gasoline? Or maybe you have a high-octane chugging sports car but don’t want to pay the premium price? An octane booster may get you the performance you want in either scenario. Octane boosters help raise the octane rating of the fuel you’ve put into your tank. So, if you’ve added 87 and the product states it can boost the octane rating of the fuel up four numbers, you in theory would have 91 octane fuel in your car. This can be helpful for those that have high-compression engines that rely on premium gas, but only want to pay mid-grade fuel prices.

For those with classic cars, you’ll want to look into certain octane boosters that help protect original engines that feature stock valve seats from back when lead based gasoline was used. Products like the AMSOIL Dominator Octane Boost contain a metallic additive called Methylcyclopentadienyl manganese tricarbonyl (good luck saying that one) that help work as a lead substitute. This long-named addition is said to create a sacrificial barrier on the stock valve seats which helps prevent recession and helps keep the engine running strong. If your classic car’s engine is rebuilt with hardened components that can handle modern unleaded gasoline, you probably don’t need this type of product.

AMSOIL Dominator Octane Boost - amsoil.com
AMSOIL Dominator Octane Boost - amsoil.com

In the end, octane boosters sound great in theory, but you’ll want to do some extra research. Make sure to purchase a well-known and reputable brand of octane booster that can give you proven results. Otherwise, paying for high-grade fuel is the better choice for your vehicle when all is said and done.

Gas Mileage Increase Additives

Gas mileage increase additives are somewhat of a “snake oil” product. If they’re advertising substantial gas mileage gains just by dumping their product into the tank, it’s more than likely not going to do anything. There may be a slight increase depending on what the product actually does, but any noticeable change in your gas mileage may just be a placebo effect.  

Cetane Boosters

Cetane Booster - amsoil.com
Cetane Booster - amsoil.com

When working with a diesel engine, you may encounter a term called cetane. Cetane ratings help indicate the combustion efficiency of diesel fuel kind of in the same way an octane rating is used for gasoline to show ignition stability. Having a higher cetane rating helps the fuel diesel burn better and produce more power. High cetane also helps reduce smoke byproducts generated by the engine (sometimes referred to as rolling coal) and adds to the achievable fuel mileage your diesel vehicle can reach.

However, most of the diesel fuel you find at the pump is only rated between 40 and 45 for a cetane value. Adding a cetane booster additive can help increase the diesel’s cetane rating in your tank. By raising the cetane to optimal performance levels, it will help your diesel engine perform better and get better fuel efficiency. Is it completely necessary to add for every fill up? Not entirely, but if you care about your big diesel truck and how it runs, it’s worth a look.

Anti-Gel Additives

Anti-Gel Additive - opti-lube.com
Anti-Gel Additive - opti-lube.com

Cold weather is the worst, especially for diesel powered vehicles. Diesel fuel naturally has wax in it that begins to crystallize when temperatures drop significantly. This crystallization results in an event coined gelling within diesel fuel systems. Gelling can lead to poor fuel flow throughout the fuel system and eventually plug the fuel filter resulting in the engine not getting the fuel it needs and not starting. Anti-gel additives help combat against this diesel gelling in your fuel system by breaking up this wax build up and preventing that wax from settling within the system when temperatures get cold enough.

Should You Be Adding Fuel Additives?

2022 Ford F-250 - ford.com
2022 Ford F-250 - ford.com

When it’s all said and done, do you really need any of these fuel additives? Basically, no. Gasoline already carries a lot of the detergents and additives needed to keep a car’s fuel system clean and maintained, so some of these products are virtually pointless to add. Any of the listed benefits from these fuel additives are minimal at best and won’t be apparent after use. When it comes to diesel, keeping it from gelling in the winter is a must, but that can be accomplished by utilizing an engine block heater or even just parking the vehicle inside when not in use.

If you really would like to try a fuel additive, go ahead. Just be sure to do your research on the product that you’re adding to your tank, otherwise you’re wasting your time and money.

Related How To Articles

How to Identify a Flood-Damaged Car

What is Apple CarPlay and Android Auto?

Buying a Car With Bad Credit

Tags:
Jesse McGraw

Jesse McGraw brings his life-long car obsession into his writing. A fun childhood that involved growing up around race tracks, working on a rusty ‘99 Dodge Dakota held together by zip ties, and collecting Hot Wheels developed into a strong appreciation for automotive history. If there is an old, obscure, or rare car, he wants to know about it. With a bachelor's degree in Web Development & Design from Dakota State University, Jesse can talk shop about car or computer specs, focusing on classic cars, imports, and car culture.

  • 1

Leave a Comment

Your email address will not be published. Required fields are marked *

[class^="wpforms-"]
[class^="wpforms-"]
[class^="wpforms-"]
[class^="wpforms-"]
[class^="wpforms-"]
[class^="wpforms-"]
[class^="wpforms-"]
[class^="wpforms-"]
Share
Tweet
Pin