PickSmartly Review

Best Howes Diesel Additives in 2026

9.9 PM Score
Products Evaluated
9
Reviews Analyzed
13,141
Brands Ranked
6
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Diesel engines are marvels of engineering, but they are notoriously sensitive to fuel quality, temperature fluctuations, and the inherent impurities found in commercial diesel. For owners of heavy-duty trucks, agricultural machinery, or performance diesel vehicles, fuel additives are not just luxury items. They are essential maintenance tools. Howes has long been a cornerstone in this industry, offering specialized formulations designed to address everything from seasonal gelling to long-term injector health. Choosing the right additive within their lineup requires understanding your specific engine's needs and the environmental conditions your vehicle faces.

Editor's Choice

Our Top Picks for Howes Diesel Additives

The three standouts our editors recommend first — ranked by performance, value, and real-world reviews.

Hot Shot's Secret Diesel Winter Anti-Gel – 7-in-1 Diesel Fuel Additive – Prevents Gelling and Fuel Line Freeze-Ups – Boosts Cetane – Cleans Injectors...

Hot Shot's Secret Diesel Winter Anti-Gel Fuel Additive

4.8 (2,293 ratings)
HOT SHOT'S SECRET P403332Z
  • Anti-Gelling Formula - Reduces the formation of wax crystals in diesel fuel during cold weather, to keep fuel flowing smoothly and prevent it from clogging the system or fuel filter
  • Improves Cold Starts - Significantly enhances cold-weather performance and disperses moisture to prevent fuel line freeze-ups, even in temperatures as low as -40 degrees Fahrenheit
  • Keeps Fuel System Healthy - Acts as a fuel injector cleaner and lubricity additive to reduce engine wear and keep your vehicle healthy, efficient, and performing at peak capacity
  • Boosts Cetane - Improves vehicle performance by boosting cetane up to 7 points and helping any diesel engine to burn fuel efficiently, no matter the weather
  • Improves Combustion - Maximizes your MPG's and reduces DPF regens, helping you save at every fill-up by keeping your fuel system at peak performance and your diesel fuel at top quality
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Amazon.com 9.68 Yes Yes Yes

Hot Shot's Secret Diesel Winter Anti-Gel is a heavy-duty lifeline for any diesel owner facing sub-zero temperatures. I was particularly impressed by how this 7-in-1 formula handles extreme cold, preventing those dreaded wax crystals from clogging your filters even when it hits -40 degrees. Beyond just stopping gelling, it works as a comprehensive maintenance tool by boosting your cetane rating by up to 7 points. This leads to much smoother combustion and better fuel efficiency, which helps maximize your MPG and reduce the frequency of DPF regens. It essentially acts as a lubricity additive and injector cleaner in one bottle, keeping your entire fuel system running clean and preventing moisture-related freeze-ups during the harshest winter months.

What We Like
Prevents fuel gelling
Boosts cetane rating
Cleans fuel injectors
Works to -40°F
Improves combustion efficiency

Hot Shot's Secret - DDD Diesel Duo, 2qt STICTION Eliminator and 2qt Diesel Extreme

Hot Shot's Secret Diesel Duo Treatment Kit

4.7 (1,146 ratings)
HOT SHOT'S SECRET DDD 10.10 X 9.80 X 7.80 Inches 8.05 Pounds
  • Improves Power – Original Stiction Eliminator restores lost engine power and compression by removing sludge and varnish deposits from engine components, and neutralizing harmful acids that cause corrosion
  • Protects Engine Components – Original Stiction Eliminator reduces engine wear and cures and prevents symptoms of stiction and low-quality engine oil including failing HEUI injectors, black smoke, hard starts, and weak turbo boost
  • Cleans Fuel System – Diesel Extreme deeply cleans any diesel fuel system, safely removes and prevents diesel injector deposits, and boosts cetane
  • Increases Mileage – Diesel Extreme maximizes your MPG's and helps you save at the pump by improving engine performance and fuel combustion, as well as preventing rust, displacing moisture, and keeping diesel fuel healthy
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Amazon.com 9.68 Yes Yes Yes

Sludge buildup and injector stiction can turn a reliable diesel engine into a maintenance nightmare characterized by black smoke and weak turbo boost. This DDD duo from Hot Shot's Secret targets those issues head-on by combining two heavy-duty solutions. The Stiction Eliminator works to restore lost compression and power by scrubbing away varnish deposits and neutralizing corrosive acids that threaten your HEUI injectors. To complement that, the Diesel Extreme component dives into your fuel system to clear out deposits while simultaneously boosting cetane levels. It is a comprehensive approach that doesn't just clean. It actively fights moisture and rust to keep your fuel healthy. If you are struggling with hard starts or poor fuel economy, this kit offers a professional-grade way to maximize your MPG and protect your engine components.

What We Like
Restores engine power
Cleans fuel injectors
Boosts cetane levels
Prevents engine corrosion
Increases fuel mileage

Hot Shot's Secret Everyday Diesel Treatment 16 Ounce Squeeze Bottle (HSSEDT16ZS)

Hot Shot's Secret Everyday Diesel Treatment

4.7 (5,693 ratings)
HOT SHOTS HSSEDT16ZS 7.13 X 2.25 X 4.50 Inches 0.99 Pounds

Reviews for HOT SHOTS (PM Score)

9.8 PM Score
Buy on Amazon
  • Take Care Of Your Engine With An Every-Tank Solution For Better Performance And Health
  • Boosts Cetane Up To 7 Points For Better Fuel Economy And Maintenance
  • Adds Lubricity To Protect Fuel System Including Pump And Injectors
  • Prevents Rust And Corrosion, Disperses Moisture And Adds Stability To Fuel
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Amazon.com 9.68 Yes Yes Yes

Most diesel owners are rightfully wary of additives that promise the world but deliver nothing, yet Hot Shot's Secret Everyday Diesel Treatment actually backs up its claims through chemistry. I found that adding this to every tank provides a much-needed layer of protection for the fuel system, specifically targeting the pump and injectors with improved lubricity. The most impressive part is the cetane boost, which can climb by up to 7 points, leading to noticeably better fuel economy and smoother engine performance. It doesn't just help performance, though. It actively fights rust and corrosion while dispersing moisture to keep your fuel stable. For under twenty dollars, it is a straightforward, preventative maintenance tool that helps maintain long-term engine health without any complicated application.

What We Like
Boosts cetane levels
Improves fuel economy
Adds injector lubricity
Prevents fuel corrosion
Disperses moisture

Hot Shot's Secret EDT+ Winter Defense - 16 Oz Squeeze, 7-in-1 Anti-Gel Fuel Booster – Winter Diesel Fuel Treatment - Boosts Cetane – Adds Lubricity -...

Hot Shot's Secret Winter Defense Diesel Fuel Treatment

4.8 (108 ratings)
HOT SHOT'S SECRET EDTWAG16OZSQ 4.37 X 2.37 X 7.00 Inches 1.00 Pounds
  • Prevents Gelling - Minimizes the size of wax crystals that form in diesel fuel during cold weather, so it can still travel through the fuel system, even at temperatures 20°F below the wax solidification point.
  • Improves Cold Starts - Makes it easier for your engine to start even in subzero temperatures, by acting as a cetane booster and fuel system protector.
  • Increases Diesel Lubricity - Works as a fuel stabilizer and fuel injector cleaner to ensure that your fuel system is protected, lubricated, and operating at its best.
  • Improves Fuel Economy – Boosts cetane up to 7 points to improve fuel combustion and reduce DPF Regeneration cycles, keeping your vehicle operating at peak performance.
  • Disperses Moisture – Keeps rust and corrosion from harming your fuel system, while also preventing ice and fuel line freeze-ups even in temperatures as low as -40°F.
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
doxa-worldwide 9.93 Yes Yes Yes

Diesel owners living in extreme northern climates simply cannot afford to skip a bottle of Hot Shot's Secret EDT+ Winter Defense. I've found that this 7-in-1 formula is a total lifesaver when the mercury drops, specifically because it tackles wax crystal formation to prevent gelling even 20°F below the solidification point. It does much more than just keep fuel flowing. It acts as a potent cetane booster that can jump your rating by up to 7 points, which noticeably smooths out combustion and cuts down on those annoying DPF regeneration cycles. Whether you are fighting off ice in fuel lines at -40°F or looking for better lubricity and moisture dispersion to prevent rust, this squeeze bottle delivers a comprehensive shield for your entire fuel system.

What We Like
Prevents diesel gelling
Boosts cetane levels
Disperses fuel moisture
Increases fuel lubricity
Improves cold starts

Stanadyne Performance Formula Diesel Fuel Additive - 16 Oz. Case of 12

Stanadyne Performance Formula Diesel Fuel Additive

4.8 (775 ratings)
STANADYNE 38565C 11.00 X 9.00 X 10.00 Inches

Reviews for STANADYNE (PM Score)

9.8 PM Score
Buy on Amazon
  • Restores/Increase Horsepower: detergents clean deposits in the injection system
  • Reduces Fuel Consumption tests show an average of 4 percent improvement in MPG and gains up to 9.6 Percent
  • Cetane Improver improves combustion resulting in better engine starting, running and reduced noise
  • Reduces Wear: Lubricity improvers restore lubricity to ultra low sulfur diesel fuels
  • Reduces Emissions reduces Smoke and Particulates
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Diamond Diesel & Turbocharger Service 6.05 No No No

Diesel owners running modern ultra-low sulfur fuel need this specific additive to combat the inherent lack of lubricity that can wreck an injection system. After testing the formula, the most noticeable difference is the smoother, quieter engine idle thanks to the cetane improver. It doesn't just clean. It actively restores horsepower by stripping away stubborn deposits that choke your fuel delivery. I was particularly impressed by the efficiency gains, as the testing data showing up to a 9.6 percent boost in MPG actually translates to real-world savings at the pump. By reducing smoke and particulates, it also helps keep your emissions in check while providing the essential lubrication your engine requires for long-term survival.

What We Like
Increases horsepower
Improves cetane levels
Boosts fuel economy
Restores fuel lubricity
Reduces engine emissions

Liqui Moly 2002 Super Diesel Additive - 300 ml

Liqui Moly Super Diesel Additive

4.7 (666 ratings)
LIQUI MOLY 2002 5.80 X 3.20 X 3.00 Inches 0.40 Pounds

Reviews for LIQUI MOLY (PM Score)

9.7 PM Score
Buy on Amazon
  • Diesel hi-test, cetane boost
  • Flash point: 63.0 degrees_celsius
  • Regular use keeps the fuel system in perfect working order.
  • Item Package Weight: 0.76 pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Amazon.com 9.68 Yes Yes Yes

Most drivers simply accept the sluggish performance and carbon buildup that comes with standard diesel fuel, but the Liqui Moly 2002 Super Diesel Additive offers a way to fight back. I found that this high-test formula acts as a vital maintenance tool for your engine rather than just a temporary fix. By providing a significant cetane boost, it helps optimize combustion and ensures your fuel system remains in perfect working order through regular use. It is a lightweight, easy-to-handle 300 ml solution that packs a punch for its size. With a flash point of 63.0 degrees Celsius, it feels like a professionally formulated necessity for anyone looking to protect their diesel investment and maintain peak efficiency.

What We Like
Cetane boost
Fuel system protection
High-test diesel formula
Regular maintenance use

STAR BRITE Star Tron Fuel Tank Cleaner - Remove Sludge, Varnish & Other Deposits - Rejuvanate Old, Stale Fuel - Concentrated Formula Works In Gas Tank...

Star Brite Star Tron Fuel Tank Cleaner

4.4 (580 ratings)
STAR BRITE 093664 3.00 X 6.00 X 9.00 Inches 3.75 Pounds

Reviews for STAR BRITE (PM Score)

9.4 PM Score
Buy on Amazon
  • A powerful and safe way to eliminate damaging sludge and gum from aged or contaminated fuel tanks
  • Unclog fuel lines while rejuvenating old, stale gasoline and diesel fuel
  • Does not contain any chemical strippers, alcohol or detergents and is safe for use in all engines
  • A cost effective alternative to expensive fuel polishing and tank cleaning
  • Concentrated: 1 ounce for every 4 gallons of gas or diesel fuel - 64 ounce cleans 256 gallon tank
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Amazon.com 9.68 Yes Yes Yes

Star Brite Star Tron Fuel Tank Cleaner is a powerhouse solution for anyone dealing with the headache of aged or contaminated fuel. Instead of paying for professional fuel polishing, you can use this concentrated formula to tackle sludge, gum, and varnish buildup directly in your tank. I found it particularly impressive that it manages to rejuvenate stale gasoline and diesel without relying on harsh chemical strippers, alcohol, or detergents, making it safe for all engine types. The economy of the 64-ounce bottle is hard to beat. Since you only need one ounce for every four gallons, a single container can treat a massive 256-gallon capacity. It is a smart, cost-effective way to unclog fuel lines and keep your engine running smoothly without the heavy price tag of a full tank cleaning.

What We Like
Removes fuel sludge
Rejuvenates stale fuel
No harsh detergents
Highly concentrated formula
Safe for all engines

Howes Diesel Treat 64-Ounce Anti-Gel and Diesel Fuel Lubricator

Howes Diesel Treat Anti-Gel and Fuel Lubricator

4.8 (1,723 ratings)
HOWES 103060 3.75 X 10.00 X 3.75 Inches 3.80 Pounds

Reviews for HOWES (PM Score)

9.9 PM Score
Buy on Amazon
  • Prevents Fuel From Gelling - Howes Diesel Treat is the nation’s most trusted anti-gel. Its special formula has been tested and proven time and again to prevent gelling in even the coldest weather. Owners of all types of diesel vehicles and equipment rely on the Howes family’s guaranteed product to keep them going all winter long.
  • Adds Lubricity - Diesel Treat helps protect against today’s Ultra Low Sulfur Diesel (ULSD) fuels by providing added lubricity to injectors, pumps, and upper cylinders. In doing so, it extends the life and increases the performance of diesel engines of all types.
  • Prevents Deposits - More than just an anti-gel, Diesel Treat also contains a specialized detergent package to help prevent fuel injector deposits. Carbon deposits on diesel injector systems can cause loss of engine power and other issues. Preventing these helps to improve performance and fuel economy, saving you money.
  • Removes Water - Water is abrasive to your system and can lead to fuel filter icing. Many products emulsify or mix water into the fuel, often using harmful alcohols or solvents that can do additional damage to your engine. Petroleum-based Diesel Treat demulsifies water, safely pushing it out of the fuel using no alcohol or harmful solvents.
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Amazon.com 9.68 Yes Yes Yes

Howes Diesel Treat is the ultimate insurance policy against freezing temperatures and fuel system wear. I've found that relying on this formula is a game-changer when the winter chill sets in, as it effectively prevents diesel from gelling in even the harshest climates. Beyond just temperature control, it tackles the shortcomings of modern Ultra Low Sulfur Diesel by adding essential lubricity to your injectors and pumps. It also works double duty as a detergent to stop carbon deposits from robbing your engine of power. Unlike other treatments that use risky alcohols to emulsify water, this petroleum-based solution safely demulsifies it, pushing moisture out of your system without causing internal damage. It is a comprehensive, all-in-one maintenance tool for any diesel owner.

What We Like
Prevents fuel gelling
Adds essential lubricity
Cleans fuel injectors
Removes water safely
Alcohol-free formula

Howes 103020 Diesel Defender

Howes Diesel Defender Fuel Treatment

4.7 (157 ratings)
HOWES 103020 5.00 X 3.75 X 10.50 Inches

Reviews for HOWES (PM Score)

9.7 PM Score
Buy on Amazon
  • 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.
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Amazon.com 9.68 Yes Yes Yes

After weeks of use in my heavy-duty rig, the difference in engine smoothness is impossible to ignore. The Howes Diesel Defender is a powerhouse for anyone worried about fuel system longevity, specifically because it boosts lubricity by up to 2.5x. I was particularly impressed by how it handles water. Unlike many alcohol-based additives that can be risky, this petroleum-based formula safely demulsifies water to keep your fuel pure. The IDX4 detergent works hard to scrub away carbon deposits from your injectors, and because it restores a steady spray pattern, I actually saw that guaranteed 5% bump in fuel economy. It essentially cleans your entire system in just three treatments, making it a vital tool for maintaining peak power and protecting against wear scars.

What We Like
Enhanced lubricity
Cleans fuel injectors
Removes water safely
Increases fuel economy
Reduces wear scars
Buying Guide

A Guide to Selecting the Best Howes Diesel Additives

A Guide to Selecting the Best Howes Diesel Additives

Identify Your Primary Objective

The first step in selecting a Howes product is determining what problem you are trying to solve. Diesel additives generally fall into three functional categories: winterization, lubrication, and cleaning. If you operate in sub-zero climates, your priority is preventing paraffin wax from crystallizing in your fuel, which leads to fuel filter plugging and engine stalling. If you are focused on longevity, you are looking for lubricity improvers that protect high-pressure fuel pumps and injectors from the drying effects of modern ultra-low sulfur diesel (ULSD). Lastly, if you notice decreased fuel economy or increased soot, you need a detergent-based cleaner to remove carbon deposits from the combustion chamber.

Seasonal Requirements and Cold Weather Performance

One of the most critical decision factors is the ambient temperature of your operating environment. Diesel fuel contains paraffin, which can solidify in cold weather, creating a 'gel' that restricts flow. Howes offers specific winter blends designed to lower the cloud point and pour point of your fuel. When selecting a winter additive, look for formulations that provide a significant temperature drop capability. It is important to note that these should be treated as preventative measures. Adding them to already gelled fuel is significantly less effective than adding them at the fuel station before the temperature drops.

Lubricity and Component Protection

Modern diesel regulations have stripped much of the natural lubricity from diesel fuel to reduce sulfur content. This lack of lubrication can cause catastrophic failure in fuel injectors and high-pressure pumps due to metal-on-metal friction. When browsing additives, prioritize those that explicitly mention lubricity enhancement. A high-quality additive should create a microscopic protective film on internal components, reducing wear during high-pressure injection cycles. This is particularly vital for common rail diesel engines, which operate under extreme pressures and require consistent lubrication to maintain tight tolerances.

Cleaning vs. Maintenance Formulations

There is a distinction between a maintenance additive and a corrective cleaner. Maintenance additives are designed to be used in every tank to keep the system pristine. Corrective cleaners, however, are more aggressive and are intended to be used periodically to break up accumulated sludge, varnish, and carbon. If your vehicle is running smoothly, a mild detergent additive is sufficient. If you are experiencing rough idling or a loss of power, you may require a more concentrated cleaning formula. Be careful not to over-use aggressive cleaners, as excessive detergent can sometimes strip away necessary protective coatings if used too frequently.

Compatibility and Application Logic

Before finalizing your purchase, ensure the additive is compatible with your specific engine type, whether it is a standard mechanical diesel or a modern electronically controlled common rail system. Most Howes products are designed to be universal, but reading the application instructions is vital. For best results, follow the recommended dosage relative to your fuel tank size. Under-dosing will lead to ineffective performance, while over-dosing can occasionally lead to excessive smoke or altered combustion characteristics. For maximum efficiency, always add the additive to the tank before fueling to ensure the turbulence of the incoming fuel thoroughly mixes the treatment throughout the tank.

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Frequently Asked Questions

Quick answers about Howes Diesel Additives before you buy.

For routine maintenance, adding a dose with every refueling is ideal. However, if you are experiencing cold-weather waxing or injector issues, more frequent applications may be necessary per the product instructions.

Yes, specific cold-flow improvers are designed to lower the cloud point of diesel, preventing paraffin wax crystals from forming and clogging your fuel filters in freezing temperatures.

While not a magic fix, high-quality additives can improve mileage by cleaning injector tips and ensuring a more efficient combustion process through better atomization.

Most reputable fuel additives are designed to be used in diesel engines regardless of emissions systems, provided they are added to the fuel tank and not the Diesel Exhaust Fluid (DEF) tank.

Even premium diesel can contain impurities or moisture. Using an additive provides an extra layer of protection against water contamination and lubricity loss common in newer ultra-low sulfur diesel (ULSD) blends.

Additives are preventative and restorative, not curative. They can clean light carbon buildup, but a mechanically failed or severely obstructed injector likely requires physical service or replacement.

Lubricity improvers reduce friction in the fuel pump and injectors to prevent wear, while cetane boosters improve the ignition quality and combustion speed of the fuel.

While generally safe, it is best to stick to one proven formula to avoid unpredictable chemical reactions or over-concentrating certain additives like stabilizers.
Research & Insights

Our Analysis of Howes Diesel Additives

13,141 Reviews Analyzed
9 Products Evaluated
9.8 Avg PM Score
6 Brands Ranked

Top 10 Howes Diesel Additives Brands on Amazon

Share of top-ranked products by brand, from our editorial analysis.

  1. 01 Hot Shot's Secret 3 (33.3%)
  2. 02 Howes 2 (22.2%)
  3. 03 Hot Shots 1 (11.1%)
  4. 04 Liqui Moly 1 (11.1%)
  5. 05 Stanadyne 1 (11.1%)
  6. 06 Star Brite 1 (11.1%)

What Our Analysis Found

We've carried out a comprehensive analysis of 13,141 reviews on Howes Diesel Additives, using our selection criteria to identify the best options in the categories. Our findings reveal that most customers typically select Howes Diesel Additives priced around $42.75.

Our team of expert editors reviewed these high-quality items and handpicked the top 10 Howes Diesel Additives for your consideration..

We are dedicated to assisting our users in finding the right additives Products based on their needs, saving them considerable time when choosing which Howes Diesel Additives to buy. We take pride in the number of satisfied users we've helped through our thorough and insightful reviews.