Are Fuel Additives Necessary?

Take a walk through any auto parts store or read any automotive magazine, and you’re likely to see any number of fuel additives or oil additives touting to “improve fuel economy,” “increase oil change intervals,” and “save you money.” Automakers, fuel distributors, and oil manufacturers are in the business of producing vehicles, fuels, and oils that work for hundreds of thousands of miles – millions of miles for over-the-road truckers. When you see oil additives marketed so, it makes one wonder if there something additive-manufacturers aren’t sharing with them or if they’re just marketing modern snake-oil.

In case you’re wondering, “snake-oil” comes from the age-old practice of marketing something medicinally useless or possibly toxic as a remedy for all manner of sickness, weakness, or disease.

Fuel additive and oil additive manufacturers, especially those making grandiose claims, are to be eyed with suspicion. They claim to employ chemistry that “coats moving parts” or “eliminates deposits,” yet the “proof” is often specious at best. Of course, their own “studies” show some improvement, but unbiased third-party studies are usually non-existent or downplayed.

The best thing that could possibly happen if you buy a bottle of fuel additive is, well, nothing at all. Innocuous blends of chemicals may indeed do no harm to your engine, which is a good thing. Many times, whatever goes into the crankcase simply evaporates over a few thousand miles, leaving the owner none the wise. Perhaps the only bad result, in this circumstance, is that you wasted a few dollars. Again, there’s almost no way to prove it, because human beings, especially hopeful ones, are horrible at being objective.

The worst thing that could happen is you actually damage your engine. Certain chemicals are absolutely not to be introduced into your fuel tank or crankcase, as they can damage sensitive electronics. Some additives have been directly linked to catastrophic engine damage. One case involves an additive claiming to “coat moving parts,” but how can it differentiate between moving and non-moving parts? Coating non-moving parts, such as oil galleries and oil sprayers, could actually block them, starving the engine for oil and resulting in expensive engine overhaul costs. That being said, there are fuel additives that are worth the price of admission, but they have very specific uses.

• If you drive a classic car, lead substitutes and octane boosters can prevent damage to cast-iron valve seats. Modern unleaded fuel doesn’t have this lubricating quality.
• If you don’t plan on using a vehicle or piece of equipment for months at a time, fuel stabilizers prevent fuel separation. All publicly-available gasoline in the United States is blended with at least ten percent ethanol, which tends to stratify over time. Adding fuel stabilizers to the fuel tanks of an RV, stored car, lawn mower, or four-wheeler is great protection during their downtimes.
• If you operate a diesel-powered vehicle in temperatures drop below freezing, 32 °F or 0 °C, diesel fuel anti-gel will keep you running. When diesel fuel gets cold, especially below-freezing, it can start to get cloudy and then start to solidify, called “gelling,” and no longer flows. Because the fuel pump doesn’t work with gel, the engine can’t start.
• Over time, particularly if the vehicle isn’t fueled at a TOP TIER gas station, will develop fuel deposits and carbon deposits. Fuel system deposits can clog fuel injectors and impact performance and fuel economy, while carbon deposits can block airways and lead to ping, detonation, and other problems. All gasoline sold in the United States comes with a minimum EPA-mandated additive blend, but TOP TIER detergent fuels have more. If you don’t regularly use TOP TIER fuel, regular fuel injector cleaner can help to restore your engine’s performance and fuel economy.

Unfortunately, despite the hype and anecdotal evidence, most additives are modern snake-oil. Just as in the old days, when many were seeking solutions to their health problems, many seek solutions to their automotive problems, whether it be poor fuel economy, high emissions, check engine light, or poor performance – and there is a seemingly unlimited number of companies willing to sell them something , even a placebo.

The only way to preserve performance, fuel economy, reliability, and longevity is to use automaker-recommended fuel and engine oil, regularly maintain the vehicle, and keep everything clean. A highly-concentrated fuel injector cleaner might restore fuel injector performance and upgrading to a quality top-brand synthetic oil might clean old oil deposits. Some additives might simply be a waste of money, which might be better spent on higher-quality oil or high-grade fuel, while others could end up costing money in engine repairs.

If you really think you need a fuel additive, consider two things. First, “If it sounds too good to be true, it probably is,” which is good direction on avoiding all kinds of hype. Second, check for independent testing, such as by consumer-advocacy groups and automotive groups. Research and reports by the Federal Trade Commission, Better Business Bureau, American Automobile Association, and Consumer Reports, to name a few, are good places to start. Sure, it’ll take some time to do the research, but when said time could prevent you from wasting your paycheck or wrecking your engine, it’s time well-invested. The great majority of drivers keep their vehicles running well without resorting to dubious performance-enhancing additives.