Model D21
The complete diesel set for tanks up to 200 litres — two Fuel Enhancers plus the Air Refiner for trucks, tractors and farm machinery.
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Model D21 at a glance
| Model | D21 |
| Fuel type | Diesel |
| Tank capacity | Up to 200 litres |
| Package contents | Fuel Enhancer (100 L) × 2 · Air Refiner × 1 |
| Installation | Drop both enhancers into the fuel tank; fit the Air Refiner at the air intake. No tools, no engine modification. |
| Activation | Starts working within about 30 minutes of installation |
| Service life | 10 years, no maintenance and no refills |
| Warranty | 12 months with serial-number registration at greentech.tw |
| Best for | Trucks, tractors and farm machinery |
| Origin | Designed and manufactured in Taiwan · Taiwan and U.S. invention patents |
Light commercial: on the road daily, saving daily
Cargo vans, trade vehicles, sales fleets — the more they run, the faster this pays.
Four sites a day; fuel and smoke inspections are both a headache.
Both ends treated — better smoke readings at inspection.
✓ Up to −85% smoke in fleet testsRun it on my fleet →
Stop-and-go is the thirstiest duty cycle there is.
Frequent starts are exactly where combustion improvement bites.
✓ Grab fleet testing: −9.5%Run it on my fleet →
Management wants cost per kilometre.
Run two vans A/B for 30 days; roll out on the numbers.
✓ UAE IFFCO: payback in 30 daysRun it on my fleet →🌿 Beyond fuel: for many fleets the main reason to buy is emissions — government bus tests measured smoke down by up to 85%, idle CO cut to zero, 9 of 10 buses passing. Inspections, carbon targets and ESG are where this device fights.
Not your scenario? 3.5-tonne and up → D20 · Heavy fleets → D51
Run the payback on your own fuel bill
India, 4 trucks, 219,793 km (2025–26)
Official rating: diesel up to 10%, gasoline 15–20% — measured higher in heavy-duty markets: Ethiopia official tests +33.6% diesel / +18% gasoline; Qatar heavy truck +34.6%. The more efficient the vehicle, the smaller the % looks — the litres still add up.
🌿 Fuel is only half the story — the emissions gains (smoke down up to 85%, idle CO to zero) carry inspection and ESG value on top.
Do not take our word for it
Government labs, fleet trials, customer letters and patents in six jurisdictions — swipe through; every card links to the source document.
Granted in 6 jurisdictions
Vietnam · USA · Taiwan · South Africa · EU · China
View certificates →+7.2% over 219,793 km
Two Indian fleets, 4 heavy trucks · 9–13 months · payback 2.4–3.1 months · 2025–26
Full case study PDF →Diesel +33.6%
Ethiopia ECAE official test · Toyota Hilux · HC −79% · 2022
Official test PDF →2.6 → 3.5 km/L
Bin Sraiya Readymix, Qatar · Mercedes heavy truck · +34.6% · 2023
客戶測試信 PDF →10% average across fleet
Hizam Al-Qahtani Transport, Saudi Arabia · Actros MP2/3/4 + Sino · "no problems" · 2025
Case studies →Smoke down up to 85%
KSRTC state buses, India · 9 of 10 passed · emissions testing
KSRTC report PDF →ISO 9001 · 14001 · IATF 16949
Made in Taiwan · certified manufacturing
ISO 9001 certificate PDF →Installed in minutes
Drop both enhancers into the fuel tank
Open the fuel cap and drop them in — they sit in the tank for their whole service life.
Fit the Air Refiner at the air intake
Place it by the air cleaner following the illustrated guide in the box.
Drive as usual
Activation begins within about 30 minutes; record fuel data over the following weeks to see your own before-and-after.
The same drop-in method applies across vehicle types.
What tests show for diesel engines
7.4% across a heavy fleet
IFFCO UAE ran six heavy trucks (550 L tanks) for one month: 7.4% average savings, device cost recovered in about 30 days.
−25–85% emissions
KSRTC government buses in India: emission cuts on nine of ten buses, and BS-II buses met BS-IV norms without engine modification.
6–12% fuel savings
California Environmental Engineering FTP-75 tests on Kenworth Class 8 and 9 heavy-duty trucks (2007–2009).
Before you order
Will it void my vehicle warranty?
No. The device is passive — no chemicals, no electronics and no engine modification — so the vehicle warranty is unaffected.
How soon will I see results?
The device activates within about 30 minutes. For a reliable before-and-after comparison, record fuel consumption over two to four weeks of normal use.
My tank is larger than 200 litres — which model do I need?
Choose D50 or D51 for tanks up to 500 litres.
How do I register the warranty?
Enter the serial number from the packaging at our product registration page. Warranty runs 12 months from registration.
Does it need maintenance or replacement?
No maintenance, no refills. The service life is 10 years; after that, simply replace the unit.
How do I know my unit is genuine?
Every genuine unit has a serial number you can verify on the registration page. Units bought outside authorized channels cannot be registered.
Ready for Model D21?
Order online, request a quote for volume, or talk to us about a structured fleet pilot.