Best Diesel Engine Cleaner for Fuel Systems and Oil Sludge

#1 · Best Overall

1. Archoil AR6400-D

Best for: Periodic injector and DPF care.

Why it ranks #1: This focused diesel fuel-system cleaner targets injector deposits and lists turbo and DPF deposit control; one 12-ounce bottle treats 30–40 gallons.

A single 12-ounce bottle treats 30–40 gallons, letting diesel owners add a concentrated cleaning step during a normal fill-up. Archoil AR6400-D targets injector deposits and DPF deposits, making it a focused option for drivers seeking fuel-system and emissions-system deposit control without changing their usual driving routine.

Pour the bottle into the fuel tank and drive normally, so application requires no separate flush procedure. Archoil recommends use every 5,000 miles or as needed, giving owners a stated maintenance interval to plan around. Its injector-cleaning action is described as restoring spray patterns for smoother running and response, while the product also targets DPF deposits. The supplied information does not give a treatment dose for tanks outside the stated 30–40-gallon range.

Skip it if you need a stated dose for a tank under 30 gallons; the listed treatment amount starts at 30 gallons.

Choose AR6400-D if you want a periodic, tank-added cleaner for injector and DPF deposits and can use the stated 30–40-gallon treatment. It is not presented as an oil-based engine flush.

Listed on Amazon as: Archoil AR6400-D Diesel Fuel System Cleaner (12 oz) Deep Clean – Injector Cleaner, Turbo & DPF Deposit Control

#2 · Best Two-Step Kit

2. Archoil Diesel Fuel System Kit

• Size: 1 Count (Pack of 2)

Best for: Two-step clean-and-maintain diesel kit.

Why it ranks #2: The kit combines AR6400-D for a deep clean with AR6500 for ongoing treatment; it is listed for diesel engines including modern HPCR systems.

Archoil pairs a deep-cleaning AR6400-D bottle with AR6500 for ongoing treatment, creating a two-step routine rather than a single additive dose. The kit is specified for all diesel engines, including modern HPCR systems, and provides separate treatment capacities for each stage.

Use AR6400-D first: its 12-ounce bottle treats 30–40 gallons for the deep-cleaning step. Then AR6500 is intended for every fill-up, with 40 ounces treating up to 400 gallons, giving owners a stated path from initial cleaning to ongoing maintenance. The listing says the kit works with diesel vehicles and equipment, including pre-emissions vehicles and modern common-rail engines. Its two-step workflow requires keeping both stages in the routine.

Skip it if you want a single-step diesel treatment; Power Service Diesel Kleen combines injector cleaning and cetane boost in one listed product.

Choose the kit if you want a stated deep-clean-then-maintain sequence for diesel vehicles or equipment, including HPCR systems. Its fit depends on following both stages rather than seeking one bottle for all treatment.

Listed on Amazon as: Archoil Diesel Fuel System Kit – AR6400-D (12 oz) + AR6500 (40 oz) – Complete Restoration For All Diesel Engines, Injector Cleaner, Lubricity Improver, DPF & Turbo Deposit Control, Cetane Booster

#3 · Best Full-System Cleaner

3. Hot Shot's Secret Diesel Extreme

• Weight: 0.45 kg
• Size: 16 Fl Oz (Pack of 1)

Best for: One-step fuel-system deposit cleanup.

Why it ranks #3: This 16-ounce fuel additive is described as cleaning the entire fuel system, removing deposits, water, and sludge, and improving cetane.

Hot Shot’s Secret Diesel Extreme addresses deposits, water, and sludge across the fuel system in one liquid treatment, while also improving cetane. The 16-ounce bottle is aimed at diesel owners seeking a broad fuel-side cleanup associated with easier starts, stronger acceleration, and smoother combustion.

Its stated action covers the entire fuel system, including removal of harmful deposits, water, and sludge, so the product is positioned beyond injector deposits alone. The formula contains cumene, which the listing connects with fuel quality and combustion efficiency. Cetane improvement is also tied to easier starts and stronger acceleration. The supplied information identifies a 16-ounce bottle but does not state gallons treated, so dosing capacity cannot be compared from these details.

Skip it if you require a published gallons-per-bottle dose; Archoil AR6400-D states treatment for 30–40 gallons.

Diesel owners seeking one fuel additive that targets deposits, water, and sludge may find Diesel Extreme relevant, particularly if cetane improvement is a priority. Its listed details do not provide a gallons-treated figure.

Listed on Amazon as: Hot Shot's Secret Diesel Extreme, 16 oz, Fuel System Cleaner

#4 · Largest Listed Bottle

4. Power Service Diesel Kleen

• Weight: 4 lb

Best for: Large-format injector and cetane treatment.

Why it ranks #4: The 64-ounce formula targets dirty injectors and deposits in HPCR and older systems, and is listed for ULSD, biodiesel, and blends.

Power Service Diesel Kleen combines injector deposit removal with cetane boost in a 64-ounce bottle, offering a large-format option for diesel owners. Its stated compatibility spans ULSD, biodiesel, and biodiesel blends, while injector-cleaning claims cover both HPCR and older fuel systems.

The product targets internal and external injector deposits and helps prevent injector sticking in both high-pressure common-rail and older systems, making its stated application broad across diesel-system types. Slickdiesel Lubricator is included to protect fuel pumps and injectors from wear linked to poor-quality ULSD. The listing also connects cleaning with restored power and fuel economy. Its 64-ounce format is clear, but the supplied facts do not specify gallons treated per dose.

Skip it if you need a published bottle coverage figure; Archoil AR6400-D specifies 30–40 gallons per 12-ounce bottle.

Diesel owners with HPCR or older systems may value the stated injector targets, cetane boost, and broad fuel compatibility. The 64-ounce bottle is substantial, but its treatment ratio is not supplied here.

Listed on Amazon as: Power Service Diesel Kleen+Cetane Boost 64 oz, Pack of 1 3064-06 Grey

#5

5. Liqui Moly Super Diesel Additive

• Weight: 6.4 oz

Best for: Cetane and fuel-system maintenance.

Why it ranks #5: This 300 ml diesel additive is described as cleaning and maintaining the fuel system while increasing lubrication and cetane.

Liqui Moly combines diesel fuel-system cleaning with a cetane-value increase, pairing deposit maintenance with a combustion-related benefit. The 300 ml Super Diesel Additive is intended for regular use, so it suits diesel owners seeking an ongoing fuel-treatment routine rather than a one-time engine-oil flush.

The product description says its additive combination cleans and maintains the diesel fuel system, while also increasing lubrication to reduce fuel-pump and injector wear. That makes the maintenance role broader than detergent action alone. Its cetane boost is linked in the supplied description to easier starting and improved engine performance. Regular use is specifically mentioned, but the available facts do not state a vehicle fuel capacity or a per-tank dosage, so buyers should not infer one.

Skip it if you need a stated gallons-per-bottle treatment; Archoil AR6400-D specifies coverage of 30–40 gallons.

Consider this for routine diesel fuel-system upkeep when cetane support and added lubrication matter alongside cleaning. The listing gives a 300 ml size but no treatment ratio, so it is less suited to dose planning.

Listed on Amazon as: Liqui Moly Super Diesel Additive | 300 ml | Diesel additive | SKU: 2002

#6

6. Mechanic in A Bottle

• Weight: 3.17 lb

Best for: Gas-and-diesel fuel-system maintenance.

Why it ranks #6: The concentrated formula is listed for gas and diesel fuel systems and says it removes varnish, shellac, and carbon deposits while dispersing water.

Mechanic in A Bottle covers gas and diesel systems, including gas-ethanol, diesel, and biodiesel blends, making its stated compatibility the key distinction for mixed-fuel equipment owners. The concentrated two-pack targets varnish, shellac, carbon deposits, and water within the fuel system.

The listing describes use in the fuel tank and names injectors, carburetors, and internal engine components as targets, giving the product a broad fuel-system maintenance role. Its antioxidant and anticorrosive package supports protection alongside deposit removal, while water dispersion addresses another listed fuel-system concern. Two 24-ounce bottles are included, but the supplied information does not state gallons treated per dose, so users cannot calculate coverage from the listed facts alone.

Skip it if you need a stated treatment ratio for diesel tanks; Archoil AR6400-D lists coverage of 30–40 gallons.

This suits owners maintaining mixed gas and diesel equipment who value the listed blend compatibility and deposit targets. Its two-bottle supply is clear, but the available facts do not establish a per-tank dose.

Listed on Amazon as: Mechanic in A Bottle for Gas & Diesel Fuel Systems 24 oz – 2 Pack Fuel System Cleaner & Stabilizer for Peak Engine Performance

#7

7. Hot Shot's Secret EDT

• Weight: 16 oz
• Size: 16 Fl Oz Squeeze

Best for: Regular-use diesel fuel treatment.

Why it ranks #7: This 16-ounce product is positioned as an everyday diesel treatment, with regular-use guidance and a listed cetane increase of up to 7 points.

A cetane increase of up to seven points gives Hot Shot’s Secret EDT a defined role in ongoing diesel fuel treatment, with listed links to fuel economy and reduced maintenance costs. Its 16-ounce squeeze bottle suits owners who want a recurring additive rather than a dedicated oil-side flush.

The product is described as an everyday treatment intended to maintain engine health and support smooth, efficient running with regular use. Its cetane boost of up to seven points connects the fuel treatment to the stated fuel-economy benefit. The listing also frames EDT as a performance-maintenance additive, rather than a deposit-cleaning flush for rings or bearings. A 16-ounce squeeze bottle is specified, but no gallons-per-dose amount is supplied in the provided details.

Skip it if you need a quantified bottle-to-tank ratio; Archoil AR6400-D lists treatment for 30–40 gallons.

EDT suits diesel owners prioritizing recurring fuel treatment and the listed cetane and fuel-economy benefits. Choose it for maintenance use rather than an oil flush; the supplied facts do not specify a tank dosage.

Listed on Amazon as: Hot Shot's Secret Everyday Diesel Treatment EDT, 16 oz

#8

8. Liqui Moly Diesel System Additive

• Weight: 1.32 lb

Best for: Two-bottle Liqui Moly diesel additive.

Why it ranks #8: This two-container listing is identified as a diesel system cleaning additive, but the supplied details do not specify treatment rate or cleaning claims.

This Liqui Moly listing supplies two 300 ml units of a product titled as a diesel detergent system additive, giving buyers a paired quantity for diesel-fuel maintenance. The provided facts identify the 5128 model and package size, but do not describe specific cleaning results or dosage.

The title identifies the product as a detergent additive for diesel, while the listing specifies two units and model 5128. That supports its placement as a fuel-side diesel treatment rather than an engine-oil flush. However, no detailed feature description, gallons-treated figure, or application interval is provided in the supplied information. Buyers can confirm the product category and pack contents, but should not assume particular injector, turbo, or DPF outcomes from these facts.

Skip it if you need named injector-cleaning and DPF claims; Archoil AR6400-D lists both targets.

This listing may fit a buyer seeking a two-unit Liqui Moly diesel detergent additive. Its supplied facts establish category and quantity, but not a treatment ratio or detailed cleaning targets, limiting use-case precision.

Listed on Amazon as: 2 x Liqui Moly 5128 motore – System Additivo detergente per Diesel 300 ml

#9

9. TRIAX Pro-Engine Flush

• Weight: 16 oz
• Size: 16 oz

Best for: Oil-change flush for diesel engines.

Why it ranks #9: This oil-based flush is compatible with four-stroke diesel engines and targets lubricant-related sludge, but it is not a fuel-system cleaner.

A maintained lubrication film is the defining feature of Triax Pro-Engine Flush, supporting a pre-change cleaning process without leaving engine parts unlubricated during the flush. Its 16-ounce bottle treats 10 quarts and is specified for four-stroke diesel and gasoline engines, making it relevant to mixed-engine households or workshops.

The oil-based formula targets sludge and deposits on piston rings, bearings, and valve-train parts while maintaining a lubrication film. Triax says it can free stuck piston rings and improve valve seating, connecting the cleaning step to compression and power restoration. The stated 10-quart treatment gives users a capacity reference before an oil service. Its application is an engine-oil flush, not a diesel-fuel-tank additive, so it suits maintenance workflows involving lubricant-related deposits.

Skip it if you want a cleaner poured into diesel fuel; Archoil AR6400-D is specified for tank application and injector deposits.

This fits owners or service shops addressing lubricant-related sludge during an oil-service workflow, especially when one product must cover four-stroke diesel and gasoline engines. It is not the choice for fuel-system cleaning.

Listed on Amazon as: TRIAX Pro-Engine Flush – Oil-Based Flush – Engine Safe (16 oz – 473 ml)

#10

10. Motul Engine Clean

• Weight: 0.18 kg
• Size: 10.1 Fl Oz (Pack of 1)

Best for: Solvent-free oil-side engine cleaning.

Why it ranks #10: This solvent-free flush is listed for gasoline and diesel engines, but its oil-additive purpose makes it a weaker match than fuel-system cleaners.

Motul Engine Clean is identified as solvent free, a useful distinction for buyers seeking an oil additive and flush rather than a fuel-tank detergent. The 300 ml liquid is described as a care-system product for engine cleaning, with sludge removal and improved oil flow named in its title.

This product belongs in an oil-side cleaning workflow: its title describes it as an oil additive and flush, and names sludge removal and improved oil flow as intended functions. The solvent-free specification gives buyers a clear formulation detail when selecting an engine-cleaning product. The listing also mentions emission-system care and engine protection, but does not provide a detailed application procedure or engine capacity, so those points should not be expanded into a specific dose or interval.

Skip it if you want a diesel fuel-tank additive; Liqui Moly Super Diesel Additive is described for diesel fuel-system cleaning.

Motul Engine Clean fits buyers looking for a solvent-free, oil-side cleaning product with sludge and oil-flow aims. The listing provides a 300 ml size but leaves application dose and engine capacity unspecified.

Listed on Amazon as: Motul Engine Clean | Oil Additive & Flush for Gasoline & Diesel Engines | Helps Remove Sludge & Improve Oil Flow | Supports Emission System Care & Engine Protection | 300ml