Archoil Diesel Fuel System Kit – AR6400-D (12 oz) + AR6500

Product Overview

The Archoil Diesel Fuel System Kit delivers a two-stage approach to diesel engine care, combining AR6400-D (12 oz) for deep cleaning with AR6500 (40 oz) for ongoing protection. This complete system is designed for all diesel engines, including modern high-pressure common-rail (HPCR) systems and older pre-emissions vehicles. It addresses common issues like injector fouling, carbon buildup, poor fuel economy, and frequent DPF regenerations by restoring fuel system efficiency and maintaining it over time. Whether you operate a light-duty truck, heavy-duty fleet vehicle, or industrial equipment, this kit supports consistent performance, smoother operation, and long-term engine reliability.

How It Works

The kit follows a simple two-step process. Start by adding AR6400-D to your first tank of fuel—this powerful cleaner strips away stubborn carbon, varnish, and injector deposits that accumulate over time. Once the initial clean is complete, transition to AR6500 at every fill-up. This maintenance formula continues to prevent deposit formation while enhancing fuel properties for optimal combustion and protection. AR6400-D treats 30–40 gallons of fuel, while AR6500 treats up to 400 gallons, making it cost-effective for regular use.

Key Features

• Two-Step Fuel System Reset: AR6400-D performs a deep clean of injectors, fuel lines, and combustion chambers. Follow with AR6500 at each refuel to maintain cleanliness and protect against future buildup.
• Injector Cleaning & Combustion Restoration: AR6400-D removes deposits that disrupt injector spray patterns, restoring proper fuel atomization for smoother idling, improved throttle response, and more complete combustion.
• Enhanced Lubricity Protection: AR6500 improves fuel lubricity by 43% as tested to ASTM D6079, reducing friction and wear on critical components such as high-pressure CP4 pumps and injector needles.
• Cetane Boost for Smoother Ignition: AR6500 increases cetane levels by up to 8 points, enabling faster ignition, reduced knocking, and quieter operation—especially during cold starts or under heavy load.
• DPF & Turbo Deposit Control: Both formulas help minimize soot and deposit formation in the diesel particulate filter (DPF) and turbocharger, supporting consistent airflow, reducing regeneration frequency, and preventing turbo lag.
• Fuel Economy Improvement: Cleaner injectors and more efficient combustion often result in measurable gains in miles per gallon, with users reporting improvements exceeding 10%.
• Biodiesel Compatibility: Safe for use with biodiesel blends including B5 and B20, without risk of additive separation or performance degradation.

Technical Specifications

• AR6400-D (Diesel Fuel System Cleaner): 12 fl oz bottle, treats 30–40 gallons of diesel fuel
• AR6500 (Diesel Treatment): 40 fl oz bottle, treats up to 400 gallons of diesel fuel
• Compatible with all diesel engines, including HPCR systems and pre-emissions vehicles
• Recommended usage: AR6400-D every 5,000 miles or when symptoms like reduced power, black smoke, or poor MPG appear; AR6500 at every fill-up
• Must be added to diesel fuel—not a standalone fuel source

Benefits & Use Cases

This kit is ideal for addressing real-world diesel engine challenges. Use AR6400-D when you notice performance issues such as rough idling, hesitation, or excessive exhaust smoke—it penetrates deep into the fuel system to dissolve deposits and restore functionality. After the initial clean, AR6500 maintains that cleanliness while improving fuel quality with every tank. It’s especially beneficial for vehicles that frequently idle, operate in stop-and-go traffic, or make short trips, as these conditions accelerate deposit formation. By keeping the DPF and turbo free of buildup, the kit helps reduce the need for forced regenerations, saving time and fuel while extending the life of emissions components. Whether you drive a pickup, delivery truck, or agricultural machine, this system supports reliable, efficient operation across a wide range of conditions.

Frequently Asked Questions

Can I use the Diesel Fuel System Kit in my vehicle?

Yes. The kit is suitable for all diesel vehicles, including pre-emissions models and modern high-pressure common-rail engines.

Should I use AR6400-D and AR6500 in the same tank of fuel?

For best results, use AR6400-D in the first tank for a deep clean. Begin using AR6500 at the next fill-up and continue at every subsequent refuel.

How often should I use AR6400-D Diesel Fuel System Cleaner?

Use AR6400-D every 5,000 miles or when performance issues arise, such as declining fuel economy, reduced power, or visible smoke.

Can the Diesel Fuel System Kit be used with biodiesel blends?

Yes. Archoil’s diesel treatments are fully compatible with biodiesel blends, including B5 and B20.

Important Notes

Always add the treatment to your fuel tank before or during refueling. Do not mix AR6400-D and AR6500 in the same tank unless performing an initial reset. Store both bottles in a cool, dry place away from direct sunlight. This product is formulated for diesel engines only and should not be used in gasoline-powered vehicles. Follow your vehicle manufacturer’s recommendations regarding fuel additive use.