Auto Parts - What Are Fuel Additives And How Do They Work?

Have you ever wondered why your snowblower won’t start in January, or why your car is idling a little rough since a cold snap started? Your fuel quality or fuel system may be compromised.

Keep reading to learn about the different types of fuel additives, what they do, and how to know which one is right for your needs.

What Are Fuel Additives?

Fuel additives are chemical compounds you can add to gasoline or diesel to address specific issues. While they’re not cure-alls, they can keep your fuel in peak condition. Most modern fuels contain some additives from the refinery, but many aftermarket products can supplement those in a variety of situations.

NAPA Canada carries a wide range of fuel and engine additives to preserve many different fuel and engine types.

Fuel Injector Cleaners

Over time, carbon deposits can build up in fuel injectors and disrupt their spray pattern, which can cause rough idling, engine hesitation, and reduced fuel economy. Injector cleaners contain detergents, like polyether amine (PEA), that dissolves and dislodges carbon deposits as it passes through the fuel system to restore normal injector function.

Use an injector cleaner when you notice symptoms like a rough idle or hesitation during acceleration, or as preventive maintenance. Add them to your fuel tank roughly every other oil change. Always follow the dosing interval on the product label.

Fuel System Cleaners

Fuel system cleaners take things one step further by targeting the entire fuel system, including the fuel tank, lines, pump, and combustion chamber. They contain much stronger detergents than fuel injector cleaners to remove build-up from every part of the fuel system.

Use a fuel system cleaner whenever you want a more comprehensive clean, especially if you have a higher-mileage vehicle.

Fuel Stabilizers

Fuel can begin to degrade if it sits for longer than 30 days. However, untreated ethanol-blended fuel usually remains stable for 30-60 days without use. Non-ethanol fuel can last up to six months untreated.

Gums, varnish, and deposits can form, and ethanol-blended fuel can absorb extra moisture and cause corrosion. Fuel stabilizers work by slowing down the oxidation process and can keep fuel fresh for up to two years.

If you store your vehicle or motorized equipment over the winter, you’ll want to have fuel stabilizers on hand. Cottage boats, ATVs, snowblowers, lawnmowers, 2-stroke equipment, classic cars, and secondary vehicles tend to sit for quite a while and are much more susceptible to degraded fuel. Before putting them into storage, add a stabilizer and briefly run the engine to circulate it through the system.

Fuel stabilizers aren’t necessary for daily drivers, since the fuel is burned well before it has a chance to degrade.

Octane Boosters

This variety of fuel additive raises the octane rating of gasoline to increase its resistance to premature detonation.

When pockets of the fuel-air mixture auto-ignite after the spark plug fires — instead of burning smoothly outward from the spark — it causes a phenomenon known as “engine knocking.” This creates a sharp, metallic pinging or rattling noise in the engine.

(Ignition before the spark fires is a related but distinct phenomenon called pre-ignition.)

High-performance and turbocharged engines that require premium fuel benefit the most from octane boosters.

Octane boosters aren’t a magic fix. Most consumer-grade octane boosters raise the rating by less than one full octane number (for reference, 91 to 92 is a one-number increase — many product labels advertise this as “10 points”), and if your engine already runs the recommended fuel grade, an octane booster likely won’t make much of a difference.

But octane boosters can be a great short-term solution for high-compression or performance-tuned engines, or if premium fuel is unavailable.

A Quick Note on Diesel Additives

Diesel has a separate additive category, including anti-gel conditioners for cold-weather gelling, cetane boosters, and lubricity additives for low-sulfur diesel. Check out our blog with a complete guide on which diesel fuel additives are best for you.

How to Choose the Right Fuel Additive

The best way to decide which fuel additive you need is to evaluate your vehicle's current symptoms or situation, then match it to the additive type. Here are a few possibilities:

• Is your vehicle about to go into storage? Choose a stabilizer.
• Are you noticing a rough idle or poor fuel economy? Opt for an injector cleaner.
• Do you want a thorough, top-to-bottom clean? Select a fuel system cleaner.
• Is your high-end engine knocking? An octane booster may help.

Most fuel additives can be added to a full tank. Just follow the dosing instructions on the label, because more is not better.

Stagnant fuel or a fuel system with contaminant build up can take a toll on your vehicle’s health and performance. For help finding the right fuel additive, visit your local NAPA Auto Parts store to speak with an automotive expert, or browse our full selection at www.NAPACanada.com.