For more thorough and powerful fuel system cleaning, complete fuel system cleaners are also available to clean not only the fuel injectors, but also the fuel pump, fuel lines, and more. Complete fuel system cleaners are also mixed with the fuel and circulated throughout the fuel system, dispersing contaminants that may be present starting in the fuel pump and working its way through the system to the fuel injectors. Once the contaminants have reached the fuel injectors, they will simply be burned with the fuel in the cylinders while the engine runs. Using a fuel system cleaner as part of a regular maintenance schedule can improve fuel economy, reduce knocking and acceleration hesitation, and restore vehicle performance.
Fuel additives have a variety of purposes and are primarily used to either preserve or enhance the fuel in a vehicle, or to clean the fuel system. In the case of diesel-powered vehicles, winter additives like diesel fuel anti-gel can also help keep fuel flowing at cold temperatures, and a variety of other products may be available to further improve the function of the fuel system in your vehicle. In this article, we’ll explore the types of fuel additives available, their specific purposes, and in what types of vehicles or driving conditions they may be best used.
Which Fuel Additives are Best for Your Vehicle?
Using fuel additives in your vehicle can help extend fuel system and engine life, but it’s important to remember that each one has a specific purpose and not all will be equally beneficial for every vehicle or driving situation. Products like fuel stabilizer may not be necessary for a vehicle that is driven daily, but a fuel system cleaner may enhance fuel mileage in nearly any vehicle, so it’s a good idea to know what goal you’re trying to achieve.
Fuel Stabilizers
The purpose of a fuel stabilizer is to help preserve fuel using antioxidants that prevent the formation of gums and lacquer in the fuel tank, fuel lines, and carburetor or fuel injectors which can occur as the fuel degrades over time. For most vehicle owners, fuel stabilizer is not necessary. When a vehicle is driven regularly, the gasoline will be burned in the engine long before it has the opportunity to degrade. However, for seasonal equipment, secondary vehicles, or collector cars that may sit for longer than three weeks at a time, adding fuel stabilizer can help prevent the fuel degradation. Fuel stabilizers can also help mitigate the harmful effects of ethanol in the fuel and inhibit corrosion to prevent damage to your fuel pump, fuel lines and hoses, or other fuel system components.
Fuel Injector Cleaners
Fuel injector cleaners, also known as fuel detergents, disperse fuel contaminants and deposits that may build up in your fuel injectors. It’s possible for fuel injectors to clog or experience a change in spray pattern due to impurities in fuel or a buildup of carbon deposits. When carbon deposits build up in the fuel injectors, it can cause clogged ports which may result in poor fuel mileage, harder starts, and a loss of power. Fuel injector cleaners help remove any contaminants and restore fuel injector operation, which can help maintain or improve your vehicle’s performance and fuel efficiency. Most fuel injector cleaner products are very easy to use, and are simply added to a full tank of fuel before the vehicle is driven.
Fuel Line Antifreeze
Fuel line antifreeze is designed to both help lower the freezing point of your gasoline and absorb water, which is often accomplished with a blend of alcohol in the antifreeze. This helps minimize the chances of freezing water in your fuel tank and fuel lines. Water freezing in the fuel system is much less common in newer vehicles as they feature closed fuel systems that prevent fuel from evaporating or moisture from entering the fuel tank. Since most fuel sold in the United States has some blend of ethanol, there is already alcohol present. However, if you are running non-ethanol gasoline, or live in an area where temperatures are often below freezing, then fuel line antifreeze may need to be a consideration for cold weather vehicle preparation. It can also be beneficial for recreational vehicles, especially boats and other watercraft where fuel has a higher risk of water exposure.
One downside to fuel line antifreeze products is that they can dry out gaskets and O-rings in the fuel system if overused, so it’s best used only in extreme climates. When adding fuel line antifreeze, be sure to follow the instructions to ensure that it’s not over-concentrated in the fuel system, as this can cause accelerated wear and other damage.
Lead Additives
If you own a classic car with an engine that was built when gasoline was still leaded, you may benefit from using a lead additive. The purpose of lead in gasoline was to minimize wear on the engine’s valve seats over time. It also boosts octane for engines with higher compression ratios and helps reduce engine knock. When maintaining a classic vehicle, it’s important to know if your engine was built with an older and softer valve seat design. These types of engines stand to benefit most from a lead substitute. It may be best to research your specific vehicle and engine specifications to determine if the use of a lead substitute is right for your engine, but this added protection can help ensure long valve life and performance in older engines when used consistently.
Octane Boosters
Octane booster fuel additives are engineered to increase your fuel’s octane rating, which can improve your vehicle’s power and efficiency. The effects of octane booster products can also be affected by how you drive your vehicle. Most vehicles may experience little noticeable difference from an octane booster product unless it is equipped with a turbocharger or if you are custom-tuning the engine for increased performance. In most cases, stock engines not designed for high performance do not need an octane booster, as octane ratings up to 91 are available at nearly every gas station, and most vehicles don’t require any more than 87 octane to run properly.
There is a common myth that octane boosters can fix engine timing issues, like preignition, misfires, or engine knock. Though raising the fuel’s octane rating can increase a fuel's ignition temperature, which in some cases can reduce symptoms of preignition and engine knock, it’s not necessarily a recommended fix for these issues. If your engine is running poorly when using the fuel octane recommended by the manufacturer, there is likely a more serious issue that needs to be diagnosed and repaired. It's best to first try a good fuel detergent that is specially formulated to fight and protect against the engine buildup that leads to preignition and engine knock. You can learn more about gasoline octane with our helpful article.
Diesel Fuel Injector Cleaners
Diesel fuel injector cleaners have much the same purpose as gasoline fuel injector cleaning products, but are designed for use in diesel fuel to disperse contaminants and restore injector spray and performance. This can maintain or regain lost power due to injector clogging or contamination, smooth rough-running engines, improve fuel economy, and many diesel fuel injector cleaners also lubricate fuel injection system components to help keep them working at their best. Select products may also boost cetane, the diesel fuel equivalent of octane, which can provide better starting as the weather begins to cool. Typically, diesel fuel injector cleaning products are designed for use in the summer, but once temperatures drop near freezing, it is best to utilize a diesel anti-gel product to ensure year-round protection and performance.
Diesel Anti-Gels and Conditioners
Diesel gelling occurs when diesel fuel changes from a liquid to a thick, gel-like substance due to cold temperatures. When the temperature of diesel fuel drops below its cold filter plugging point, the suspended gels in the diesel fuel will collect on the fuel filter and essentially starve the engine of fuel. One way to prevent this is to add a diesel fuel anti-gel or diesel fuel conditioner with anti-gel additives. This will help minimize the risk of crystallization and fuel gelling for better cold weather performance. Your diesel vehicle’s manufacturer may also have specific maintenance recommendations for your application, so be certain to check your owner’s manual to see how to best care for your diesel in the winter.
Diesel Fuel De-Icers
If your diesel fuel has already gelled enough to stall your vehicle, a diesel de-icer can melt the ice in the fuel system and relieve the wax blockage on the fuel filter enough to allow fuel to flow freely again. Some anti-gels also have de-icing capabilities, but most are made for prevention and will not work as quickly in an emergency situation. Diesel rescue products contain additives designed to de-ice and free fuel filters in a matter of minutes, and can also be used preemptively. In most cases, once a vehicle has stalled from ice in the fuel system, a diesel de-icing product will have to be added directly to the filter to work as it should, and the rest of the product will be added to the fuel tank for continued cold weather protection. Most diesel fuel contains some amount of water from condensation in storage tanks and other means of water ingress, so it's always best to attempt to prevent fuel filter blockage by utilizing the correct additives or keeping a diesel de-icing product on hand before the cold weather sets in.
Shop the Best Fuel Additives for Your Vehicle
Hopefully this helps you understand the differences between the variety of fuel additives available for your vehicle. If you need assistance finding any maintenance chemicals, repair parts, supplies, or tools to complete your fuel system maintenance, stop by your local O’Reilly Auto Parts for the best advice and to view our complete inventory, or shop fuel additives online. If you're not comfortable using fuel system treatments yourself, you can also use our Find a Repair Shop tool to find a trusted shop near you, or stop by your local store and one of our parts professionals will be happy to recommend a shop for your repair.