The 10 Best Octane Boosters
This wiki has been updated 30 times since it was first published in February of 2017. Many high-performance, racing, and luxury vehicles require a more refined fuel for safe operation than is commonly available at standard gas pumps. In fact, the right octane booster can prevent a high-compression engine from detonating and causing catastrophic failure. Remember to use caution around all flammable substances and always consult local laws to ensure compliance. When users buy our independently chosen editorial recommendations, we may earn commissions to help fund the Wiki.
March 02, 2021:
For starters, if you're not already clear on this, very few of these are legal for use on the street. Out of a decently wide selection of track-oriented choices, Boostane Premium is one of the few that's limited to 100 octane, and is the one we recommend for keeping your street-legal hot rod performing well and safely. Its relative, Boostane Professional, is highly effective for actual racing, though, able to enrich fuel up to 116 octane. For something a little less expensive, Gold Eagle 104+ is awfully tough to beat, and for many scenarios performs just fine- it also promises not to damage catalytic converters, for weekend warriors whose vehicles also pull daily driver duty. Alternatively, Royal Purple Max Boost isn't the most high-octane choice, but its consistency, reasonable price, and good reputation make it one of the most popular on the market.
September 19, 2019:
Removed MG Xylene because of availability concerns and because it is not meant to be used as a fuel additive on its own. Removed VP Fuels Cetanium because it is a cetane booster for diesel fuel, not an octane booster.
Added the Gold Eagle 104+ and the Lucas LUC10026 because they are both very affordable and effective. They are cheap enough that you do not need to switch over to racing fuel in the long term. As an added bonus, neither uses MMT which is linked to health concerns from emissions testing.
While many of these products claim fantastical results like horsepower increases and such, the reality is that they really only restore the functionality that is lost when proper octane ratings are not used. High-compression engines require fuel that has a high enough resistance to auto-ignition. The 'horsepower increase' and the lack of detonation only result from giving the engine what it needed to operate properly in the first place. A common misconception is that higher octane corresponds to higher energy potential - it doesn't. In fact, you need to burn more high-octane fuel than low-octane fuel per unit of weight to achieve the same amount of energy release. In many cases, you'll need to richen your air/fuel mixture to achieve the best output.
Octane boosters are not legal for street use and should only be used for off-road and track purposes. There may be additional restrictions given local legislation. Engine tuning should only be performed by trained automotive technicians to avoid personal injury or damage to equipment.
Everybody Gets Gas Once In A While
If there are a lot of those molecules in one space, under high pressure, they explode.
Most drivers regularly experience the joys of refilling their gas tank. This involves pulling into the station and performing a certain ritual that leads to the squeezing of a handle. Perhaps you then take this time to squeegee the windshield or check the tire pressure. The tank fills, you put your phone away, and hopefully remember to hang the nozzle up instead of driving off and ripping it violently from the pump. But do you know what you really just put in your car?
All gasoline adheres to a set of standards that make it safe and effective. Different specific ingredients result in slightly different products, though. Different companies create unique formulas based on availability and cost of materials, and chemists adjust these blends to achieve specific properties. And it's important to many drivers that they know exactly what's in their fuel.
Gasoline contains a variety of different chemicals. Hydrocarbon molecules, made exclusively of (surprise!) hydrogen and carbon, form such high-potential bonds among their atoms that when introduced to heat, they instantaneously oxidize, or burn. If there are a lot of those molecules in one space, under high pressure, they explode. Hydrocarbons are the part responsible for the "BOOM."
A class of chemicals called detergents cleans the motor's internal passageways, dissolving various deposits that could steal horsepower, thus leaving older vehicles with plenty of room to breathe. In too high of concentrations, these chemicals can inhibit the performance of high-powered engines. The right balance of these two substances can make all the difference in performance and engine health.
Thousands Of Tiny Explosions: What Could Go Wrong?
You probably recall the set of numbers situated on the gas pump's buttons. That's the octane rating. The name refers to how a given blend's properties compare to those of a chemical known as isooctane. Incidentally, consumer-grade fuel doesn't necessarily contain any actual octane molecules. And contrary to popular belief, a higher number doesn't indicate more energy or a hotter temperature. The number refers specifically to how resistant a fuel is to knocking and detonation.
If neither of those is the culprit, it's imperative to get the timing checked, as it can slip out of time after driving a distributor-timed system for many miles.
Detonation is when the air/fuel mixture reaches a high enough pressure inside the combustion chamber to spontaneously explode before the spark plug actually ignites it. This is extremely problematic, because the crank shaft hasn't yet turned far enough at this point to enter the next cycle of the engine. This is commonly known as backfiring, and it can result in anything from a loud, yet otherwise meaningless noise, to a steel piston literally shooting directly through a car's hood. This is to be avoided at all costs.
As a side note, the above doesn't apply the same to diesels, which actually use that detonation to operate, rather than an igniting spark. Diesel engines are, however, helped along by a glow plug, and one should always be aware of their turbodiesel's required cetane levels, to ensure that this all-important explosion occurs at exactly the right pressure.
Knocking occurs when there's a pocket of air/fuel mixture that manages to escape the initial reaction. When this lost, flammable blend ignites a few milliseconds later, you can hear a slight tapping or pinging coming from the engine bay. In extreme cases, it sounds like someone's shaking an old tin can with coins in it. If you ever hear this noise, it's imperative to take it easy, and take a few steps to prevent it from reoccurring. Like with detonation, the buildups found in older vehicles can cause pinging, as can low-quality fuel. If neither of those is the culprit, it's imperative to get the timing checked, as it can slip out of time after driving a distributor-timed system for many miles. Alternately, whenever you modify a vehicle's fuel, air, or spark delivery, you'll have to re-evaluate what timing is necessary to keep your combustion chamber safe. But hopefully it's just the fuel mixture, because that's an easy fix.
When The Pump Won't Cut It
A lot of today's models call for higher than unleaded variety fuel. This can mean increased performance and efficiency, but it can also be a headache. There are several reasons you don't see many Ferraris in the middle of South Dakota, and among them is the utter lack of appropriate gasoline. Furthermore, after spending innumerable hours designing and tuning a sprint car, you'd better believe that racing technicians know exactly what formula will give them the best shot at victory. As such, there's a range of additives on the market designed to customize the fuel type to suit your vehicle and how you use it.
Some additives only meagerly increase actual octane levels, but offer enhanced detergent activity.
At the end of the day, be aware of what these products can and cannot do. Many autos require high-octane fuel, but beyond the manufacturer's recommendation, you're likely just wasting your money. On the other hand, using too low of a grade can easily damage high-compression motors. Many modern cars do have anti-knock sensors that prevent serious damage, but you shouldn't rely on them, as they're merely fail-safes.
Pay attention to just how strong the product in question is, as well as its intended purpose. Some additives only meagerly increase actual octane levels, but offer enhanced detergent activity. These can reduce knock by cleaning the engine, but in the long run they won't have the desired chemical effect. More advanced options can significantly boost octane, but may be misleading if they use less-than-ideal hydrocarbons such as ethanol. And none of these products is designed to add a sudden speed boost to any car into which it's poured.
Performance auto professionals and (totally legal) street racers alike would be well-served to stick with brands that feature transparency, a good pedigree, and many satisfied customers. The proper research, along with a little bit of math, will help keep your gas from detonating, and keep your car running safely for longer.