Honda Accord
Japan Test
- Before:9.9 km/L
- After:12.6 km/L
A Japanese-engineered coolant device that improves combustion efficiency on every engine cycle. No chemicals, no maintenance, no engine modifications — drop it in your coolant reservoir and start saving on petrol or diesel from day one.
Enter your driving habits below to estimate your monthly fuel saving with FuelMarble.
What is fuel efficiency? How far your vehicle travels per unit of fuel. Typical cars average 35–50 mpg (UK) (≈ 15–22 km/L).
Typical range: 7–15%. Actual results vary by vehicle and driving style.
Verified in real-world road tests across Japan, Indonesia and China. More complete combustion means fewer litres burned per kilometre.
Typical drivers reduce their monthly fuel bill by 7–15%. Actual saving depends on vehicle type, mileage and fuel conditions.
Once installed in the coolant reservoir, FuelMarble requires no refills, no power source and no servicing — ever.
Engineered in Japan over 10 years. FuelMarble's minerals do not degrade or wear out.
Verified by Japanese government-standard emission tests. FuelMarble stabilises combustion temperatures, enabling more complete fuel burn — leaving significantly less harmful gas in the exhaust.
CO is a toxic gas produced when fuel does not burn fully. FuelMarble stabilises combustion temperatures so more carbon oxidises to CO₂ — the harmless by-product — instead of escaping as CO.
Unburned hydrocarbons and nitrogen oxides are the primary causes of smog and respiratory harm. By completing the combustion cycle, FuelMarble reduces both by up to 98% in verified Japanese government-standard tests.
FuelMarble is not a fuel additive or a chemical — it is a precision-engineered mineral device with two decades of proven performance data behind it.
Adopted globally since 2002. From personal cars in Japan to commercial fleets across Asia, Europe and the United Kingdom.
In 2008, Japan's Fair Trade Commission investigated 19 fuel-saving product companies for unsubstantiated advertising claims. All 19 received cease-and-desist orders — except one. FuelMarble's underlying technology was the only product excluded, because it was the only one supported by peer-reviewed scientific data.
10+ years of R&D at the Kurume Institute of Technology. Validated across more than 20 independent real-world fuel consumption tests on multiple continents.
Independent tests across Japan, Indonesia and China consistently show 17–28% fuel efficiency improvements. Results vary by vehicle type, driving conditions and mileage.
Japan Test
Japan Test
Indonesia Test
China Test
FuelMarble's mineral technology improves coolant performance, allowing the engine to burn fuel more completely — improving efficiency by up to 15% with a single installation.
Place the FuelMarble unit inside your vehicle's coolant reservoir tank — the translucent plastic tank under the bonnet. Important: this is the coolant reservoir, not the fuel tank. No tools, no mechanic, no engine modifications required.
FuelMarble's minerals improve coolant performance, stabilising combustion temperatures across the engine cycle. The engine burns fuel more completely and efficiently with each stroke.
Experience improved fuel efficiency as the coolant system reaches full operating temperature — typically after 150–200 km of driving. Lower fuel consumption, reduced emissions, and smoother engine operation with zero ongoing maintenance.
When will I notice the difference? Most drivers experience the improvement after 150–200 km of driving, as the coolant system reaches full operating temperature and the mineral technology fully activates.
FuelMarble works with any engine that has a coolant reservoir — from personal cars to commercial fleets, agricultural machinery to marine vessels.

Reduce daily fuel expenses for personal cars and improve engine smoothness.

Promote vitality and reduce fuel overheads for tractors and farm generators.

High-mileage courier fleets. Effective after 150–200 km running.

Heavy-duty performance for trucks and haulage fleets. ROI typically after 150–200 km.

Compatible with heavy fuel oil engines. Expect 7–15% consumption reduction.
Two sizes cover every vehicle class — from personal cars to heavy haulage. Use the guide below to choose the correct size.
Best for sedans, SUVs, and small delivery vans.
Standard commercial light trucks.
Install two L-Size units for engines in this class.
Required for heavy haulage and industrial machinery.
For passenger cars, delivery vans & light vehicles
For SUVs, heavy-duty diesels, fleets & large vehicles
No mechanic. No modifications. No ongoing maintenance. FuelMarble installs directly into your vehicle's coolant reservoir and works permanently from day one.
Locate the coolant reservoir under the bonnet — the translucent plastic tank, not the fuel tank. Twist off or unclip the cap to open.
Place the FuelMarble unit inside the coolant reservoir and close the cap. No tools, no mechanic, no engine modifications required.
Start driving normally. Most drivers notice the improvement after 150–200 km as the coolant system reaches full operating temperature and the minerals fully activate.
Start saving on fuel today. Contact us for a personalised recommendation.