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, 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, including Internal Diesel Injector Deposits (IDID), from forming on your injectors. Additionally, this alcohol-free injector cleaner safely removes water, leaving only pure fuel to burn. Diesel Defender also guarantees a minimum 5% increase in your fuel economy. There’s nothing better than a product guaranteed to save you money!

Available sizes:

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 many on the market, Diesel Defender is the ultimate choice for heavy duty vehicles. It provides protection by significantly reducing wear scars, with independent lab* results confirming 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 and prevent future deposits from forming. The removal of these deposits keeps the diesel fuel system performing optimally and increases power.


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 minimum 5% increase in fuel economy.


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.

Other Features 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 minimum 5% increase in fuel economy
  • Warranty safe and effective for all diesel emission systems
  • Contains no alcohol or harmful solvents
  • Why Use Howes Diesel Defender?

    Whether you’re a heavy-duty driver, owner of a big ol’ pick-up truck, or someone who takes your family on country-wide RV trips, you’re likely familiar with diesel fuel and its benefits over gasoline. Diesel engines are more efficient than gas engines and last much longer than their gasoline counterparts, making them ideal for larger trucks and vehicles. When you’re hauling with an 18-wheeler or pushing through the waves with your boat on the weekends, 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 Fuel (ULSD) is severely lacking in lubricity, which 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 packed with the vital lubricity you need. It contains 2.5x more lubricity than most products of its kind, protecting your entire fuel system better than any other. Armed with superior IDX4 Detergent, it also provides you with the strongest cleaning available. By lubricating your system, destroying and preventing deposits, and safely removing water, Diesel Defender gives your vehicle unrivaled protection, power, and performance all year round.


Truck HD Trucks

Tractor Tractors

Construction Construction



Part # Size Treat Rate
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 injector cleaner for your diesel engine. Perhaps you’ve been under the impression that your vehicle only needs to be treated in the winter when an anti-gel is necessary. But warm weather treatment is just as critical, though often overlooked. A clean and well lubricated system is imperative all year round in order 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.  


  • Why Does Lubricity Matter?

    Lubricity is the measure of the reduction in friction and wear by a 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 as well as ignite the fuel to power your vehicle. Excess friction can cause damage to these parts which can lead to 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 and many others 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 to safely remove 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 cause the destruction of 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, leaving 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 while prolonging 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 be used 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 for 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 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) due to extreme heat and tight clearances within the system. These deposits can form on your injectors causing coking and other damage. Uneven injector fuel spray patterns can lead to excess unburned fuel, which costs you precious fuel economy. IDX4 Detergent is formulated to rapidly remove all harmful deposits, including IDIDs, to keep the diesel fuel system clean and performing optimally. Whether you’re using untreated summer fuel or winter fuel treated with Diesel Treat, Diesel Defender will work to improve the performance of your vehicle.


Find Diesel Defender at numerous locations nationwide.

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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Howes offers a complete line of additives and lubricants designed to keep you on the road.