Product Overview
Archoil AR6400-D Diesel Fuel System Cleaner is a highly concentrated fuel additive manufactured by Archoil, designed specifically for modern diesel engines. Its primary purpose is to deep-clean the entire fuel system—including injectors, turbochargers, and the diesel particulate filter (DPF)—by removing carbon buildup, soot, and internal diesel injector deposits (IDIDs). It targets diesel vehicles of all types, including light-duty trucks, commercial vehicles, and high-mileage passenger cars equipped with advanced emissions control systems. The manufacturer claims AR6400-D can restore lost power, improve fuel efficiency (with test data showing up to a 7% MPG increase), reduce turbo lag, extend component lifespan, and uniquely, remove carbon from the DPF—a feature not commonly found in other diesel additives. At a price point ranging from roughly $75 for a 12-ounce bottle (treating up to 40 gallons), it positions itself as a mid-to-premium range product, emphasizing proprietary chemistry and measurable engine benefits for diesel owners seeking both maintenance and performance improvements.
Detailed Assessment
Functionality & Benefits
Rating: 5/5
AR6400-D offers a comprehensive cleaning action, targeting critical areas like injectors, turbos, and the DPF. Its most distinctive benefit is its ability to clean the DPF, reducing costly regens and preventing premature failures—a claim supported by manufacturer and independent testers. Users report notable improvements in engine performance, smoother acceleration, restored fuel efficiency, and less smoke, even on older or high-mileage diesels where carbon buildup is most problematic.
Technology & Innovation
Rating: 4.5/5
The proprietary detergent blend, including a proven cetane enhancer (2-EHN), distinguishes AR6400-D from generic cleaners. Its combustion-resistant formulation allows cleaning agents to survive in-cylinder processes and reach the DPF—an innovative feat among fuel additives. While the chemistry is advanced, the primary mechanisms involve established detergent and cetane technologies rather than novel molecular breakthroughs.
Ease of Use
Rating: 4.5/5
Application is straightforward: simply add the specified dose to the fuel tank every 5,000 miles, making it suitable for both DIY owners and fleet operators. There’s no need for special tools or mechanical intervention. The only caveat is that optimal results require adherence to dosing intervals and following up with maintenance doses (e.g., AR6500) as recommended by Archoil.
Market Popularity
Rating: 4/5
AR6400-D enjoys strong endorsements in enthusiast communities, online forums, and YouTube reviews. It’s especially popular among owners of turbo-diesel pickups, vans, and performance-modified diesels. While not as ubiquitous as some long-established brands, its reputation for DPF and turbo cleaning has carved out a loyal following, particularly among those with DPF or injector issues.
Customer Satisfaction
Rating: 4.5/5
Verified customers consistently report that AR6400-D delivers on its key claims. Positive reviews highlight restored power, reduced regen frequency, and improved fuel economy. Detractors occasionally question whether perceived improvements are due to cetane boost or a placebo effect, but technical test data and before/after driveability reports support overall satisfaction, especially on vehicles with prior performance issues.
Competitive Comparison
Rating: 4/5
Compared to products like Hot Shot’s Secret Diesel Extreme and the more widely available Stanadyne Performance Formula, AR6400-D’s DPF cleaning capability sets it apart. Hot Shot’s Secret offers similar injector and turbo cleaning, as well as cetane boosting, but does not specifically target soot removal in the DPF. Stanadyne is known for injector lubrication and cleaning but lacks claims about DPF performance. AR6400-D is positioned as a specialized solution where DPF or turbo fouling is a concern—though it comes at a higher price point.
Performance Results
Rating: 4.5/5
Lab and user data indicate a measurable 7% increase in fuel economy post-treatment, with tangible reductions in turbo lag, smoother idle, and fewer forced DPF regens. On vehicles with heavily fouled injectors or DPFs, AR6400-D can result in immediate driveability improvements. Effects may be less dramatic on well-maintained or newer vehicles, but ongoing use helps prevent buildup and maintain peak performance.
Value for Money
Rating: 4/5
At $75 for a 12-ounce treatment, AR6400-D is a premium-priced product. However, when factoring in the cost of DPF replacement ($2,000–$10,000) or turbo repairs, its preventative benefits provide strong justification for the price. For diesel owners experiencing frequent regens or power loss, the upfront cost is offset by the potential for significant repair savings and improved engine longevity.
Verdict
Archoil AR6400-D Diesel Fuel System Cleaner is among the most comprehensive diesel fuel additives available, uniquely combining high-concentration detergents and a proprietary chemistry that targets not only injectors and turbos, but also the diesel particulate filter—a critical advantage for modern diesels prone to DPF clogging. Its strengths lie in its ability to restore power, improve fuel economy, and prevent costly repairs by addressing carbon build-up at multiple points in the fuel system. Although some users may not notice dramatic changes if their engines are already well-maintained, the product excels as both a curative and preventative treatment—especially for vehicles showing signs of regen frequency, turbo lag, or rough idle. Its premium price is justified for owners of late-model diesel trucks, vans, and commercial fleets who seek to extend component life and avoid major repairs. For older diesel cars and light-duty pickups, its benefits are most evident in systems with visible performance decline. Overall, Archoil AR6400-D is Recommended, earning a 4.5/5 star rating for its industry-leading functionality, innovation, and proven customer results.
