The D21 is engineered for diesel tanks ranging from 101 to 200 liters (approximately 27–53 gallons). It's ideal for light commercial vehicles, SUVs, light-duty trucks, vans, and mid-size boats. If your tank is smaller (under 100L), consider our D10/D11 models. For larger tanks (around 500L), our D50/D51 series is a better fit.

The D21 uses patented ceramic technology that emits far-infrared energy inside your fuel tank. This breaks down diesel molecule clusters, reducing viscosity and creating finer fuel atomization. The result? More complete combustion in your engine — which means less wasted fuel, lower emissions, and measurable mileage improvements. Independent tests show 5–25% fuel savings, depending on vehicle condition and driving habits.

No — the D21 is a physical device, not a chemical additive. The fuel enhancer unit sits inside your diesel tank (avoiding the fuel level sensor), and the air intake filter installs in your intake system. Both work together to optimize combustion. There's nothing to pour, mix, or refill — just install once and you're set for up to 10 years.

While we provide a detailed installation guide, we strongly recommend professional installation — especially for commercial fleets. The fuel tank unit must be positioned to avoid interfering with the fuel level sensor, and the air intake filter requires proper placement to maintain airflow. A qualified technician ensures optimal performance and avoids potential issues.

Absolutely. The D21 has been certified by TÜV Rheinland (Germany) and tested by Taiwan, among other international bodies. It's a non-invasive device — no engine modifications required — and has been deployed in major fleets including KSRTC (India government buses), IFFCO (UAE heavy vehicles), and Volvo/Mercedes fleets in Portugal. The ceramic material is inert, stable, and requires zero maintenance over its 10-year lifespan.

The D21 is a B2B product designed for fleet operators, distributors, authorized partners, and commercial vehicle owners. We do not offer free trials or single-unit consumer sales. If you operate a light commercial fleet (delivery vans, service trucks, marine vessels) or are an importer/distributor interested in volume orders, we'd love to talk. Contact us with your fleet size, vehicle specs, and timeline for a tailored quote.

The D21 is designed for a 10-year service life with zero maintenance. Once installed, the ceramic technology continues to work passively — no filters to change, no parts to replace. After a decade, you can simply replace the unit if you're still operating the same vehicle or vessel.

Real-world results vary based on vehicle age, engine condition, driving style, and load patterns. Independent fleet tests report fuel savings ranging from 5% to 25%. For example, IFFCO's UAE heavy vehicle fleet averaged 7.4% monthly savings (5–13% range), while a Saudi logistics fleet saw 18% improvement. We recommend tracking your own baseline mileage for 2–4 weeks before installation, then comparing post-install performance over the same period.

Yes, we ship worldwide and welcome bulk orders from fleet operators, distributors, and EPC contractors. Pricing, lead times, and shipping terms are customized based on order volume and destination. To receive a quote, please provide: your company name, location, fleet size or order quantity, and preferred timeline. Our sales team (Rita) will follow up with detailed pricing and partnership options.

The D21 is designed to work independently and does not require additional fuel additives or devices. However, it is compatible with standard diesel fuel and can be used alongside routine engine maintenance practices. For best results, ensure your engine is in good working condition — clean filters, proper oil levels, and regular servicing will maximize the efficiency gains from the D21 system.

The D21 is engineered for diesel tanks between 101–200 liters (roughly 27–53 gallons). This makes it ideal for light commercial vehicles like delivery vans, SUVs, pickup trucks, light-duty trucks, and mid-sized boats. If your tank is smaller (under 100L), check out our D10/D11 models. For larger tanks (200L+), the D50/D51 series is a better match.

The D21 comes with two components: the fuel enhancer (goes inside the tank) and the air intake filter (installs in the air intake pipe). Drop the fuel enhancer into your diesel tank, avoiding the fuel level sensor float to prevent gauge interference. The air filter clips into your air intake system—consult the installation guide included in the box. While the process is straightforward, we recommend professional installation by a mechanic or fleet technician to ensure optimal placement and performance.

Nope—zero maintenance required. The ceramic technology inside the D21 has a lifespan of approximately 10 years under normal operating conditions. There are no filters to change, no chemicals to refill, and no ongoing costs. Just install it once and let it do its work.

No, it's not an additive. The D21 uses proprietary ceramic formulations that emit far-infrared energy to break down diesel molecule clusters and reduce fuel viscosity. This allows for finer atomization during injection, leading to more complete combustion. The result: better fuel efficiency, lower emissions (HC, CO, NOx), and reduced carbon buildup. Think of it as a physical enhancement to your fuel system, not a chemical one.

Absolutely. The D21 is a non-invasive, passive device—it doesn't alter your engine, ECU, or fuel injection system. It's been TÜV Rheinland certified and deployed in thousands of commercial vehicles worldwide, including government fleets in India (KSRTC) and corporate fleets in the UAE (IFFCO) and Portugal. The ceramic material is inert, won't degrade, and poses zero risk to your fuel pump, injectors, or tank lining.

Fleet tests around the world have reported fuel savings ranging from 5% to 25%, with most operators seeing gains in the 7–12% range. Actual results depend on your vehicle's age, condition, driving habits, load patterns, and maintenance history. Newer, well-maintained vehicles tend to show smaller but consistent gains; older vehicles with incomplete combustion often see more dramatic improvements. We don't offer guarantees on specific percentages—this isn't a one-size-fits-all magic bullet—but the data from thousands of deployed units speaks for itself.

No, the D21 is specifically formulated for diesel fuel systems. For gasoline engines, we offer the G10/G11 series (for ~100L tanks) or the G10A (for smaller tanks up to 60L). For motorcycles and small engines under 20L, check out our G-Ball (gasoline) or D-Ball (diesel) products. Each fuel type has different molecular characteristics, so using the correct model is essential for performance.

Yes, we do! Greentech is a B2B-focused brand, and we work closely with fleet operators, authorized distributors, and commercial buyers worldwide. Pricing varies based on order volume, deployment timeline, and your region. To request a quote, please contact us with your company details, fleet size (number of vehicles and tank capacities), and estimated order quantity. Our sales team will get back to you with a tailored proposal. Note: We do not offer free trials or pilot programs—verification happens through an initial commercial order.

We ship globally to fleet operators, distributors, and commercial buyers. Delivery times vary by destination—typically 5–10 business days for most regions, though customs clearance and remote locations may add time. Once your order is confirmed and payment processed, we'll provide tracking information. For large or time-sensitive fleet orders, reach out to discuss expedited options.

It's all about tank size. The D-Ball is for small diesel engines under 20L (like generators or small equipment). The D10/D11 handles tanks up to 100L (compact cars, small vans). The D21 is designed for 101–200L tanks (light commercial vehicles). For heavy-duty applications with 500L+ tanks—like Class 8 trucks—you'd need the D50/D51 series (often 2–3 units per vehicle for dual-tank setups). Match the model to your tank capacity for best results.

The D21 is engineered for diesel vehicles with 101–200L (roughly 27–53 gallon) fuel tanks. This typically includes light commercial trucks, SUVs, vans, pickup trucks, marine vessels with mid-size tanks, and light-duty construction equipment. If your vehicle's tank falls within this range, the D21 is the right fit. Need help sizing? Contact us with your tank capacity and we'll confirm the best match.

The D21 uses patented ceramic technology that emits far-infrared waves to break down fuel molecule clusters, reducing viscosity and enabling finer atomization. This means your diesel burns more completely in each combustion cycle — more energy from every drop, less wasted fuel. The included air intake filter further optimizes oxygen flow. Together, they create the conditions for cleaner, more efficient combustion. Real-world fleets report 5–25% fuel savings, though your results will depend on vehicle condition, driving habits, and current fuel efficiency.

Installation involves placing the D21 fuel enhancer inside your diesel tank (avoiding the fuel level sensor float) and fitting the air intake filter into your air intake duct. While an installation guide is included, we strongly recommend professional or technician-assisted installation to ensure correct placement and avoid any interference with tank sensors or air flow. Incorrect installation can affect fuel gauge accuracy or performance.

The D21 fuel enhancer is a solid ceramic device — not a liquid additive. It contains a proprietary blend of ceramic minerals that release far-infrared energy when in contact with diesel fuel. There are zero chemicals introduced into your fuel system, so there's no risk of clogging filters, corroding injectors, or voiding warranties. The ceramic is inert, stable, and lasts approximately 10 years with zero maintenance. TÜV Rheinland and certified.

The D21 works on both older and newer diesel vehicles. In fact, older engines often see the most dramatic results because incomplete combustion and carbon buildup are more common. For example, India's KSRTC successfully upgraded aging BSII buses to meet BSIV emission standards using Greentech technology. That said, the device doesn't repair mechanical issues — if your engine has serious problems, address those first for best results.

The D21 has an operational lifespan of approximately 10 years under normal use. There's no maintenance required — no cleaning, no refills, no replacements. Once installed, it works continuously as long as fuel flows through your tank. After 10 years, performance may gradually decline, at which point you can replace the unit.

Global fleet deployments report fuel savings between 5–25%, with emissions reductions up to 85% (HC, CO, NOx). Your actual results will vary based on your vehicle's current condition, driving style, load patterns, and baseline fuel efficiency. Vehicles in poor condition or with heavy carbon buildup often see bigger improvements. We do not offer custom ROI calculators for individual inquiries — if you're running a fleet and want projections, contact us with your fleet size, tank specs, and timeline for a detailed assessment.

No. Greentech is a B2B product, and we do not provide free trials, risk-free pilots, or client-funded proof-of-concept programs. The way customers validate the product is through an initial commercial order. If you're a fleet operator, distributor, or institution interested in deploying D21 systems, contact us with your company details, fleet size, and timeline — our team will provide a commercial quote and discuss deployment terms.

We welcome inquiries from authorized distributors and regional partners. However, distributor pricing and territory rights depend on whether we already have representation in your target region. Please provide: (1) your company name and type of business, (2) full list of countries/regions you're targeting, and (3) estimated first-order volume and timeline. Our sales team (Rita) will review current distribution arrangements in those areas and respond with applicable terms. We do not discuss distributor pricing or grant territory rights via chat — this is handled case-by-case to protect existing partners.

We ship internationally to fleet operators, distributors, and commercial buyers. Lead times and shipping terms vary by order size and destination. For volume quotes, delivery schedules, and freight arrangements, please contact us directly with your location and quantity requirements. Pricing and shipping details are provided after we assess your order profile.