Diesel Defender

Diesel Defender 100% guaranteed

Diesel Defender

Diesel Fuel Lubricator & Injector Cleaner with Advanced IDX4 Detergent

When you need the best defense against low lubricity and harmful deposits, the choice is clear. Turn to Howes Diesel Defender for maximum lubrication and superior cleaning.

Packing 2.5 times more lubricity than most competing products, Defender protects and extends the life of your system. Defender’s state-of-the-art IDX4® Detergent both cleans and prevents all deposits from forming on your injectors. This includes Internal Diesel Injector Deposits (IDID), which can otherwise be difficult to prevent and remove.

Additionally, this alcohol-free injector cleaner safely removes water, leaving only pure fuel to burn. Diesel Defender also guarantees a 5% increase or more in your fuel economy. There’s nothing better than a product guaranteed to save you money!

Available sizes:

15 oz 32 oz 64 oz

WARNING: Cancer - www.P65Warnings.ca.gov



Adds Up To 2.5x More Lubricity

With more lubricity than any other Howes product and others on the market, Diesel Defender is at the top. It is the ultimate choice for heavy-duty vehicles.

It protects your system by significantly reducing wear scars. Independent lab* results have confirmed Defender-treated fuel outperformed the US (520mm) and more stringent European (460mm) standards. *via the wear scar test for ASTM D975 High Frequency Reciprocating Rig (HFRR)


Cleans Fuel Injectors

Uses superior IDX4® Detergent to attack and destroy even the toughest carbon deposits. When used as directed, Diesel Defender is designed to clean the entire fuel system within three treatments. It also helps prevent future deposits from forming. The removal of these deposits keeps the diesel fuel system performing optimally and increases power.

Discover all the differences an injector cleaner diesel fuel truly needs can make with Diesel Defender.


Increased Fuel Economy Guaranteed

By safely removing water, Diesel Defender leaves only pure fuel to burn. Your clean injectors then allow for a steady spray pattern, so none of that fuel is wasted. When used regularly, Diesel Defender guarantees a 5% increase in fuel economy or more.


Removes Water

Many products emulsify or disperse water and frequently use alcohols or solvents that can do damage to your engine. Diesel Defender is a premium, petroleum-based product that demulsifies water, safely removing it from diesel fuel.

Benefits Include

  • Provides maximum lubricity in injectors, pumps and upper cylinders
  • Uses IDX4® Detergent to remove all types of injector deposits, including IDIDs
  • Prevents future deposits from forming
  • Safely removes water, leaving only pure fuel to burn
  • Reduces exhaust emissions and boosts engine performance and power
  • Guarantees a 5% increase or more in fuel economy
  • Warranty safe and effective for all diesel emission systems
  • Contains no alcohol or harmful solvents
  • Why Use Howes Diesel Defender?

    Heavy-duty truck drivers and diesel pickup owners generally know their fuel systems well. But even casual RV drivers and automobile enthusiasts understand fuel differences. So, you’re likely familiar with diesel fuel and its benefits over gasoline.

    Diesel engines are more efficient than gas engines. They tend to last much longer than their gasoline counterparts, making them ideal for larger trucks and vehicles. Whether behind the wheel of a semi-truck or a weekend skiff, you’re going to be looking for power. Diesel fuel offers you just that.

    Perhaps one of the few downsides of diesel engines is how expensive they can be to repair. They have intricate fuel pumps that are prone to harmful injector deposits.

    Today’s Ultra Low Sulfur Diesel (ULSD) Fuel is severely lacking in lubricity. This can lead to the premature wear of injectors, pumps, and upper cylinders. Luckily, there are ways to protect and extend the life of your diesel engine.

    One of the easiest ways is to use quality additives such as a diesel lubricity additive. Howes Diesel Defender is an unmatched diesel fuel additive packed with the vital lubricity you need. It contains 2.5x more lubricity than most products of its kind. It is designed to protect your entire fuel system better than any other.

    Armed with superior IDX4® Detergent, Diesel Defender also provides you with the strongest cleaning available. By lubricating your system, destroying and preventing deposits, and safely removing water, you keep things in working order. Diesel Defender gives your vehicle unrivaled protection, power, and performance all year round.


HD Semi Truck HD Trucks

Tractor Combine Tractors

Construction Excavator Construction

Recreational Vehicle RV

Light Duty (5) Pick Up Trucks


Part # Size Treat Rate
103024 15 oz. 1 oz. to 5 gal.
103022 1 quart 1 quart to 160 gal.
103020 1/2 gal. 1/2 gal to 320 gal.


You may have questions about the importance of using a lubricator and diesel injector cleaner for your diesel engine. Perhaps you have been led to believe you only need to treat your fuel during the winter. While gelling can be a major issue for diesel vehicles, it is not the only one. So, while anti gel is important in cold weather, it’s not a complete solution. And warm weather treatment is just as critical, though often overlooked.

A clean and well-lubricated system is imperative all year round to maintain power and performance. Read the following FAQs to understand more about why it is important to treat your fuel in the warmer months. With these insights, you can keep your diesel injector clean and your engine running its best with ease.

  • Why Does Lubricity Matter?

    Lubricity is the measure of the reduction in friction and wear by a lubricant. It is one of the primary benefits of additives like our Diesel Defender diesel injector lubricant.

    Today’s ULSD fuel lacks vital lubricity. Low lubricity can lead to premature wear of injectors, pumps, and upper cylinders. These moving parts work together to circulate fuel around your engine. They also ignite the fuel to power your vehicle.

    Excess friction can cause damage to your engine’s parts. This can lead to a loss in fuel economy, expensive repairs, and unwanted downtime. Ultimately, low lubricity leads to a slow or poorly-working engine regardless of outdoor temperature.

    Diesel Defender provides maximum lubricity to your fuel. It contains 2.5x the amount of lubricity of any other Howes product. It also bests many other diesel fuel injector cleaners and lubricators on the market. Defender helps to protect your system and provides superior power and performance.

  • Is Water In Fuel Always Harmful?

    Yes. Water is detrimental to fuel and your engine at all times of the year. You may be using Diesel Treat anti-gel during the winter. This is a great first step toward safely removing water to prevent fuel filter icing. But icing is not the only problem water can cause.

    Water is always corrosive to your entire system and can even destroy injector tips. Especially during warmer weather, water helps create the perfect environment for microbial growth. It is both timely and expensive to remove algae and bacteria once it has developed in your system.

    Removing water from your system helps protect and prolong the life of your engine. Alcohol-free Diesel Defender safely removes water by demulsifying or pushing it out of your fuel. This leaves only pure fuel to burn.

    According to major engine manufacturers, demulsification is the preferred method to remove water molecules from diesel fuel. Diesel Defender protects your diesel all year long. You can trust Diesel Defender to keep your system clean and efficient in the short term. You can also rest assured it is working to prolong the life of your engine in the long term.

  • Can I Use Howes Diesel Treat and Diesel Defender at the Same Time?

    Yes. All Howes products are safe to use together because they are 100% petroleum-based and made with no alcohol or harmful solvents. Over-treating is also not harmful with any Howes diesel product.

    Use Diesel Defender before, during, or after treating with Diesel Treat. This will offer extra cleaning and lubricity to give you an added boost of power. While Diesel Treat provides some similar benefits as Defender, it is mainly used in the winter as an anti-gel.

    Though Defender does not contain an anti-gel, it contains a highly concentrated lubricity package. This formulation is designed to provide you with maximum lubricity and protection. It also contains IDX4® Detergent to give you the strongest cleaning available. IDX4® Detergent both cleans existing deposits and prevents future deposits from forming.

    Regardless of the weather, High Pressure Common Rail (HPCR) systems are prone to Internal Diesel Injector Deposits (IDID). This is due to extreme heat and tight clearances within the system. These deposits can form on your injectors causing coking and other damage.

    Uneven diesel fuel injector fuel spray patterns can lead to excess unburned fuel, which costs you precious fuel economy. Our specialized diesel fuel injector cleaner with IDX4® Detergent, works to fight this. It is formulated to rapidly remove all harmful deposits, including IDIDs. This process keeps the diesel fuel system clean and performing optimally.

    Without question, as far as fuel additives go, it is the best diesel fuel injector cleaner for the widest range of use cases.

    Whether you’re using untreated summer fuel or winter fuel treated with Diesel Treat, rest assured. Diesel Defender will always work to improve the performance of your vehicle.

  • When Should I Use Diesel Defender?

    It is safe to use Diesel Defender diesel injector lubricant and cleaner at any time. There is no specific optimal temperature to wait for or need to delay engine use.

    Whenever you want to removeharmful carbon deposits or buildup from your injector system, don’t hesitate. Doing so can cost you engine performance or even lead to engine damage.

    Simply mix in some of our Diesel Defender with your fuel to enhance your engine’s makeup. We are confident you’ll feel the immediate boost in engine performance and efficiency. With diesel engines, you are safe to use our diesel fuel additive whenever the system needs optimizing.


Keep your diesel injectors clean. Discover a diesel injector lubricant like no other. Find Diesel Defender at numerous locations nationwide and try it for yourself.

Have questions or comments about this or other Howes premium-quality products? We want to hear from you! Contact us today for more information.

Fuel Savings Calculator

Diesel Defender (64 oz. Bottle) suggested retail
Total treatment cost
Total Saving from 5% gain in fuel economy


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