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You probably picked a diesel-powered vehicle on two fronts. First, it’s more cost-effective. Cars running on gasoline are initially cheaper, but they need frequent servicing. Soon enough, the expenses related to the latter can catch up.
Second, it’s eco-conscious. Diesel fuel, especially the ultra-low sulfur (ULSD) type, is cleaner now than its older counterparts. However, some experts like Dr. David R. Boyd still point to the toxic emissions that can come from diesel engines.
So it’s a mixed bag of pros and cons. But it’s been your loyal companion since you got the key from the car salesman. It deserves only the best diesel fuel additive for cleaning and maintenance. To optimize engine performance, look only for the best available options money can buy.
Table of Contents
- Our Pick
- Best Overall: Hot Shot’s Secret Diesel Extreme
- Best Overall Runner-Up: Stanadyne Performance Formula Diesel Fuel Additive
- Best Value: Royal Purple Max-Clean Fuel System Cleaner and Stabilizer
- Best Value Runner-Up: Archoil AR6200 Fuel Treatment
- Best Budget: Lucas Oil Fuel Treatment
- Best Budget Runner-Up: Howes Diesel Treat Diesel Conditioner & Anti-Gel
- Should You Put Additives in Diesel Fuel?
- What is the Best Winter Diesel Fuel Additive?
- What are the Factors to Consider When Buying a Fuel Additive?
- What is the Best Fuel Additive?
Best Diesel Fuel Additive in 2021
1. Hot Shot’s Secret Diesel Extreme
Boasting of a 6-in-1 detergent formula, the Diesel Extreme is a fuel additive that works on entire fuel systems. Dirt and deposits can clog the cylinders and lines, not just the injectors. This clean and boost solution cleans your fuel system parts, restoring them in good condition. Then it makes them work at peak performance.
Its high concentration helps eliminate internal diesel injector deposits (IDIDs). At the same time, it can fix or prevent the failure of other fuel system components. This premium solution contains a lot of power in one bottle.
As low-sulfur diesel (LSD) fuel becomes more and more common, you will need an effective cleaner to deal with potential problems. For instance, microbial growth can gain momentum in low-sulfur environments. So you may encounter a build-up of fungus, bacteria, and mold in your tank. Water can also get in and lead to corrosion. And there’s one additive that can defy these occurrences.
Cetane-boosting capabilities also feature in this product. It can improve your cetane rating by 7 points. It enhances a host of other functions, such as horsepower, fuel economy, and combustibility. It does away with excessive black smoke as well. During temperature drops, treating your fuel with this one can reduce cold starts.
Manufactured by Hot Shot’s Secret, a renowned brand in the automotive engine repair industry, the Diesel Extreme is a preferred item for pros and owners. It is high-quality yet affordable. A 16-ounce bottle costs around $13. For your maintenance needs, you can stock up on gallons of this good stuff.
Hot Shot’s Secret Diesel Extreme is Suitable For:
To treat 40 gallons of diesel fuel, you only need 2 quarts or 16 ounces of this product. You can buy in gallons and apply it every six months. This product is compatible with various diesel vehicles and engines, including agriculture, construction, marine, racing, and small engine diesel.
- It cleans dirt and deposits in your fuel system components, including the injector, cylinders, and lines.
- It enhances overall performance, particularly cetane rating and fuel economy.
- It is a premium formula from a trusted brand yet offered at an affordable price.
- Its packaging can be disappointing for a premium fuel additive from a top brand.
- Its effect is not equal or consistent across diesel engines and vehicles.
- It has a strong, ammonia-like odor that can put off some users.
2. Stanadyne Performance Formula Diesel Fuel Additive
Best Overall Runner-Up
For diesel engines using the common rail injector system, the Stanadyne Performance Formula Diesel Fuel Additive is a top choice. It is designed to deal with Internal Diesel Injector Deposits, improving horsepower as a result. It can also fix or reduce the effects of corrosion that low-sulfur diesel (LSD) fuel causes. It’s a multipurpose diesel additive for your modern car’s needs.
Adding to its list of strengths is its ability to enhance your engine’s cetane rating. After application, drivers observe that their engine starts running smoothly and without noise. This product also restores fuel efficiency. Watch its impact on your miles per gallon (MPG), gaining you around 4% more. The maximum boost it can bring is pegged at 9.6%.
Aside from cleaning, reducing wear, and stabilizing fuel, it can lower your emission of smoke and particulates. It is also a dependable companion in cold weather conditions. One treatment for 25 gallons of fuel only requires a bottle (16 ounces). You can buy in bulk to get more savings since this formula is recommended for use six times a year. A set containing a dozen costs a little under $100.
Take note that sellers can only ship this on the ground across the continental U.S. Air shipping is prohibited because the product is considered a hazardous chemical.
Stanadyne Performance Formula Diesel Fuel Additive is Suitable For:
Engines relying on ultra-low-sulfur diesel (ULSD) fuel can be treated with this additive. It also works on vehicles running on biodiesel fuel with up to B20 or 20% approved bio content approved. User reports say it is effective on the LLY engines found in trucks. This formula does not contain alcohol.
- It can treat the parts of an entire engine, improving horsepower, fuel economy, and cetane rating, and emissions, among others.
- It can clear away the Internal Diesel Injector Deposits (IDID) typical of common rail injectors.
- It is an affordable multipurpose formula that is compatible with ultra-low-sulfur diesel and biodiesel fuels.
- It is not effective for all kinds of diesel engines. But it reportedly works on the LLY engines found in trucks.
- Air shipping is prohibited because this product is considered a hazardous chemical.
- It comes in a new bottle that does not allow you to see the water level.
3. Royal Purple Max-Clean Fuel System Cleaner and Stabilizer
Deep cleaning multiple parts of your fuel system is Royal Purple Max-Clean‘s forte.
Its penetrating power can clear away deposits in fuel injectors. A clean fuel injector can spray full mists into the engine, which makes the latter run more efficiently. Once you treat your diesel fuel with this one, the formula will also work to prevent clogging, as well as common injector issues like hesitating and stalling, in the future.
Other auto parts also benefit from this overall solution. It works on the combustion chambers, carburetors, and intake valves. A series of fleet tests showed that this one could restore fuel economy by an average of 3.2% and raise horsepower by an average of 2.6%.
Experience the eco-friendly advantage with one application, which produces 18% less carbon monoxide, 13% less nitrous oxide, and 12% fewer hydrocarbons. It does this without harming your vehicle emissions equipment. Try it and see what an EPA (Environment Protection Agency) and CARB (California Air Resource Board) compliant product can do.
This fuel system additive can accommodate both diesel and gasoline engines, whether old or new. It covers different types such as 2-stroke, 4-stroke, naturally aspirated, turbocharged, and supercharged. You can mix it with any fuel, including ethanol blends or biofuel.
Compared to the more expensive variants, like Chevron and BG, this option is cost-effective for car maintenance. Run your engine on one can or 20 ounces every 10,000 miles.
Royal Purple Max-Clean Fuel System Cleaner and Stabilizer is Suitable For:
This formula complements a broad spectrum of engines, from diesel to gasoline, old to new, 2-stroke and 4-stroke, and naturally aspirated and turbo. It can treat many types of fuel, including ethanol blends or biofuel.
- It can penetrate the dirt and deposits in many auto parts, not just the fuel injector.
- It can be used to clean your fuel system regularly, especially if you have no access to higher-quality fuel.
- It can improve engine performance starting with fuel economy, horsepower, and emissions.
- It is compliant with the emissions standards of EPA and CARB.
- Compared with other premium brands, it is a more cost-effective solution for maintenance.
- It does not come with a nozzle, which makes it difficult to pour into the tank.
- Drivers may experience the results differently depending on their engines.
- Some users found no improvements in idling.
4. Archoil AR6200 Fuel Treatment
Best Value Runner-Up
The highly concentrated Archoil AR6200 Fuel Treatment offers an array of benefits to your car. It gets rid of the gunk in injectors and pumps while lubricating the upper cylinder. It acts as a detergent or dispersant to treat leftover diesel fuel that has gone bad. This improves fuel efficiency and protects your fuel system, especially if your vehicle has been idle for a while.
For a complete burn, this solution eliminates the sludge and enables your combustion chambers to work like new. In turn, you can end up with enhanced power and response. The upgraded process also frees the engine, turbo, and emissions systems from future soot buildup. This makes for a great option for storing fuel during cold seasons.
Another issue that plagues newer diesel fuel systems is corrosion, which can be partially caused by deposits. This product can extend the life of your engine by dealing with the culprit before it creates complications such as component failure. If your vehicle is fitted with a DPF (Diesel Particulate Filter), your DPF regeneration is shortened, resulting in an MPG (miles per gallon) boost.
This all-in-one product can save you money since you don’t need to buy injector cleaners, cetane boosters, and lubricants separately. All it takes is one gallon to treat 10,000 gallons of gas, diesel, or carbon-based fuel. That puts it at Â¼ ounces per 20 gallons.
One key element that’s missing is a better way to pour this into deep-neck tanks. The screw-on tube cap provided may not be enough for some people.
Archoil AR6200 Fuel Treatment is Suitable For:
This is an additive for both diesel and gas, as well as carbon-based fuels. It even works on smaller engines, such as generators, lawnmowers, leaf blowers, and string trimmers. Check out the tech sheet on the Archoil website.
- It fully burns fuel as well as soot and varnish to improve fuel efficiency.
- It can prevent corrosion in fuel system components, protecting them, and preventing failure.
- It caters to diesel, gas, and carbon-based fuels. Even smaller engines can benefit from this one.
- One treatment requires a small amount of this additive.
- Its screw-on mouth may not be enough to fill deep-neck tanks with ease.
- The newer formula does not seem to last as long as the former.
- Some say it equals the cost you save on fuel, so it just amounts to a breakeven.
5. Lucas Oil Fuel Treatment
Made by a recognized name in repair and maintenance, Lucas Oil Fuel Treatment is an overall formula that comes in pocket-friendly packages. It is a fuel system cleaner and lubricant in one. It removes buildup in your fuel injector and carburetor, allowing for a smoother drive and efficient combustion.
This blend of oils and additives also works as a fuel conditioning agent for vehicle and equipment diesel engines. It deals with the issues that come up in LSD and methanol, neutralizing their effects, while fulfilling federal low-sulfur requirements itself. This fuel additive promotes low exhaust emissions. If you’re preparing for a smog test, you can apply this to your fuel system.
Further, this product can extend the life of your auto parts, including fuel injectors, carburetors, fuel pumps, rings, and cylinder walls. Boost your power and miles with a quick tune-up with this one. You can get most out of every bottle because it does not contain alcohol, solvents, or kerosene. Treat your oil every fill-up or once a month, whichever fits your current needs.
One 5.25-ounce bottle is enough, with each application costing you under $10. You can double the dosage depending on the car you own. Every drop is used with this option. And take note that it comes with a hassle-free kit. The only thing to watch out for is your wallet, as you may be tempted to hoard.
Lucas Oil Fuel Treatment is Suitable For:
Any vehicle that runs on gasoline or diesel can be treated with this fuel additive. Smaller, non-road machines that rely on diesel are also covered.
- It neutralizes the negative effects of toxic emissions, low sulfur, and methanol.
- It extends the life of fuel injectors, fuel pumps, rings, and cylinders.
- It caters to both gasoline and diesel engines.
- It is a budget-friendly option.
- Due to its popularity, some people manufacture fake versions of this product.
- You may have to use it every time you fill up or at least once a month.
- It may not have an effect on cold starts.
6. Howes Diesel Treat Diesel Conditioner & Anti-Gel
Best Budget Runner-Up
Last but not least, Howes has a contender in this space with the Howes Diesel Treat & Anti-Gel. It does not only lubricate fuel injectors, fuel pumps, and upper cylinders but also prevent the gelling of diesel fuel during the cold and freezing months.
When temperatures are low, the weather can cause the paraffin in diesel to solidify. This solution has water-removing properties that can demulsify the fuel and separate the water from it. This way, the fuel does not gel, especially during winter. The fuel filters remain unclogged as well. Among those found here, this offering is the only anti-gel variant.
This petroleum-based additive does not contain alcohol or damaging solvents. It is safe to use on diesel engines that rely on ULSD ad biodiesel. After application, it can boost the cetane rating and result in a smoother engine. It can also prevent power loss, the white smoke coming from the exhaust, and rough idle. However, not every user will experience the same effects.
In some cases, users may notice an improvement in their gas per mileage. You only need one bottle to treat up to 150 gallons of diesel fuel. That would set you back $10 per bottle.
This anti-gel mixture is backed by 100 years of expertise in manufacturing performance fluids for auto parts. You can rest easy knowing that it has high-quality ingredients and that it was created using today’s most reliable technologies.
Howes Diesel Treat Diesel Conditioner & Anti-Gel is Suitable For:
This fuel additive is compatible with a variety of vehicles and non-road equipment, such as trucks, RVs (recreational vehicles), construction vehicles, tractors, and home heating oil systems. All you need is 32 ounces to treat 150 gallons of diesel, and biodiesel blends up to B-20.
- It prevents the gelling of diesel fuel during the cold and freezing months.
- It can lubricate and extend the life of injectors, pumps, and other fuel system components.
- It does not contain alcohol and is safe to use on diesel engines.
- It is easy on the pocket.
- It is more effective as an anti-gel but not as an overall fuel system cleaner.
- It is inconsistent in boosting power and fuel efficiency.
- Its packaging may require proper handling to avoid spillage.
Should You Put Additives in Diesel Fuel?
The short answer is yes and no. Here’s a quick backgrounder to explain what we mean.
Diesel is no longer the dirty, black smoke-producing fuel of yesteryears. Since 2010, highway vehicles have been required to run on ULSD (ultra-low sulfur diesel). In 2014, the Environment Protection Agency (EPA) also laid out that non-road locomotive and marine (NRLM) engines must use ULSD.
On top of these changes, diesel engines have components like particulate filters to trap the pollutants. The engines themselves have become more efficient, case in point: the common rail system.
So, should you put an additive in diesel fuel?
Given all the advancements diesel has achieved, new cars are pretty much in shape and do not need additives. Well-maintained ones may not require this formula as well. Instead, these fuel additives will work best on defective and poorly maintained cars. You may have to apply them, too, if you often drive your vehicle.
A variety of vehicles in the industry use diesel every day. And their owners, operators, and drivers need to store the fuel for a longer time. However, the recommended maximum life for diesel is six months.
If you stock up on the fuel, neglect your vehicle, drive it daily, or all of the above, you might encounter some issues with your engine. Now, LSD and ULSD are notorious for deposits and inadequate lubrication. But you may also experience lower cetane rating, cold flow, and other signs of degradation.
In such cases, you may need to turn to additives.
No additive can do it all.
Those that boast of multi-functional features may not show any difference in some factors. This is why even though the options in this review claim to be all-in-one, we lay down their targeted effects and how they fare.
Further, you’ll get more from specialized fuel additives that work excellently on one problem. If a product has more than one, choose based on your most urgent concern.
Types of Diesel Fuel Additives
More or less, you have an idea about what each type does. We mentioned some of their capabilities in the reviews. Read on to learn more.
Fuel Injector Detergents
Hard starts and slow acceleration can signify an engine problem. In some cases, these are all symptoms of a dirty fuel injector. Diesel can leave deposits in this auto part. Dirt, molds, and bacteria, among others, can also accumulate in the area. Detergents are the most effective way to unclog your injector and improve the performance of your fuel system.
You probably don’t have access to high-quality diesel all the time. The fuel can lose some of its favorable characteristics due to long storage in the refinement and distribution facilities. To prevent further breakdown, degradation, and oxidation of diesel, you can treat it with fuel stabilizers upon filling up.
When you need to “add cetane” you are trying to raise your cetane rating. This change simply means that the fuel burns more quickly when you add chemicals such as cetane boosters. Therefore, it promotes engine efficiency. If an additive has the right blend for this situation, the ingredients undergo combustion at lower temperatures, which then ignites the rest of the fuel.
Rust and corrosion can occur on your engine components, causing them to function less optimally and, worse, fail to work ultimately. But what causes corrosion? Microbes and the byproduct of water in the fuel are two of the common culprits. Your fuel additive with corrosion-inhibiting properties may target to prevent either.
The paraffin or wax in your diesel fuel can gel or accumulate in cold temperatures. If you want to improve cold starts or combat gelling, you need an anti-gel additive. This solution is useful, especially during winter or if you live in a place that is chilly for most of the year. Aside from improving overall engine performance, this formula can also unclog diesel particulate filters.
What is the Best Winter Diesel Fuel Additive?
To prevent gelling during cold and freezing months, you need an anti-gel that promotes the demulsification of the fuel. This separates the water component from the fuel component. We found the Howes Diesel Treat Diesel Conditioner & Anti-Gel as the best winter diesel fuel additive.
It’s petroleum-based and contains no alcohol or damaging solvents. One bottle can treat up to 150 gallons of diesel, or biodiesel blends up to B-20. It is safe to use on a range of engines, including those found in highway vehicles, as well as non-road vehicles and equipment. It can also work on your heating oil system at home.
It can also unblock diesel filters to keep your emissions low and compliant.
What are the Factors to Consider When Buying a Fuel Additive?
Diesel fuel additives typically contain detergents and dispersants. These ingredients are safe to pass through engine parts. Make sure they are not mixed with alcohol, though, as the latter can cause significant damage to your system. It can leave your vital components vulnerable. This chemical is not compatible with many materials, such as rubber and neoprene. It can affect compression, as well.
We talked about EPA regulations earlier. To comply with environmental standards, diesel engines should pass an emissions test. If the fuel additive does not reduce harmful and hazardous emissions, it is canceling out any other benefits it may provide. To determine if a solution is safe or not in this regard, check the label for confirmation. An EPA seal of approval can also help.
Type of Diesel Fuel Additive
We enumerated the different types of fuel additives in the previous section. If you didn’t skip that part, you probably know which type you should be searching for. Many fuel additives are advertised as all-in-one solutions. So you should pick the one that performs strongly in your area of concern.
We also talked about this under additive types. In addition, you should examine the packaging to see if the product contains dispersants or emulsifiers. Anti-gel options like the one from Howes are labeled as such to make things easier for you. The best kind should have a proven record of separating water from the fuel, as well as removing it to prevent the growth of microbes and corrosion.
Fuel additives may be multi-functional, but this does not mean they are compatible with all types of diesel fuels and engines. We specify compatibility in the reviews so that you can make the right purchase decision off the bat. The best diesel fuel additive can cater to most types of engines and fuel systems. Some can work on diesel cars in general.
Another point we stressed in the reviews is the frequency of application. Some products require treatment each time you fill-up. But the best ones tend to produce longer-lasting effects, so you’re only asked to apply them at certain intervals, e.g., every n months or after n miles.
Your choice will also depend on the time and budget you set aside for maintenance work of this kind.
Speaking of budget, you can buy a bottle or a dozen depending on your needs and preferences. On average, the regular size costs between $20 and $50. But the ones you can bulk-buy can fall under the $20 price point. See if getting your preferred additive in a bigger bottle can save you money and space (where you’ll store those containers) in the long run. These retail at $50-$150 apiece.
What is the Best Fuel Additive?
We don’t want to pre-empt your decision-making process. As much as we’re able to categorize each product on our list, we also want you to choose the right fit for you. So we suggest that you treat the labels as guidelines, not rules that you need to follow to the letter.
That said, determining the best diesel fuel additive for you is our ultimate goal. To help you with that, we would like to acquaint you with the popular brands that made our list.
Established in the past decade, Archoil represents an advanced way of manufacturing lubricants and fuel treatments. It integrates nanotechnology developments into its products in an effort to provide diesel engines with progressive solutions. It can accommodate the needs of engine vehicles in a variety of settings: automotive, industrial, agricultural, marine, motorsports, etc.
Its team holds office in Oxford, Connecticut.
Hot Shot’s Secret
The forte of Hot Shot’s Secret is in the area of repair and maintenance. Its additives are engineered to fix engine issues, helping customers save on repair costs. It boasts of its research and development processes and facilities. And it claims that nothing leaves its building with the brand’s logo on it without being the best, giving you an idea about how rigorous the testing is.
Its team holds office in Mount Gilead, Ohio.
A hundred years ago, this company started manufacturing lubricants. It has expanded its offerings to fuel cleaners, enhancers, and other blends and additives since then. One of its popular lines is the Diesel Treat, which has an anti-gel variant that is perfect for treating fuel when the cold weather is being hard on your vehicle.
Its headquarters is based in North Kingstown, Rhode Island.
This manufacturer has made a name in and out of the United States for its additives and lubricants. Its additive line, the Lucas Oil Fuel Treatment, is preferred by the truckers in the country. But it’s also grown popular in other areas, such as the consumer, industrial, and agricultural sectors.
The brand’s production was born in Corona, California.
Targeting consumer and industrial engines, Royal Purple manufactures synthetic lubricants for a range of applications. These include automotive, racing, and other high-performance fields. It was acquired by the refining company Calumet Specialty Products Partners in 2012.
The company’s HQ is found in Porter, Texas.
With over a century of expertise in manufacturing on its back, Stanadyne shows no sign of slowing down. It has been serving the automotive industry with fuel additives that cater to both gasoline and diesel engines. The record-holder for the bestselling line is the Stanadyne Performance Formula.
The company’s main office is located in Windsor, Connecticut.
A good diesel additive can clean and protect your injector, but the best one can do more. It is multi-functional, just like Hot Shot’s Secret Diesel Extreme, our top pick for this category. This product already leads the list of the best diesel injector cleaners. With its 6-in-1 detergent formula, it can also enhance engine performance and protect auto parts.
If you are searching for other functions aside from clearing away injector deposits, you can try this solution, as well as the other offerings in this article. Each of them has its own target areas to improve. Some work on a wide array of diesel engines and fuels, while others are limited to a few areas.
Either way, they all have something to offer the diesel car drivers.
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Howdy! I’m John Robinson from Levittown, New York. I am a mechanical engineer for 15 years and already had an established car repair company. I developed a personal relationship with cars since I was a kid. I always love the sounds and smell emitted by a car or truck and even at construction machinery. Since then I have been married but my love for cars only grew.