FuelMarble S — Fuel Efficiency Device for Cars & Vans | Made in Japan
FuelMarble S — Fuel Efficiency Device for Cars & Vans | Made in Japan
Couldn't load pickup availability
| 🇯🇵 Made in Japan | ✅ JFTC Approved | 📦 Free UK Shipping | 🔄 30-Day Returns | 🔒 No Engine Modification |
🚗 Not sure which size you need? See the FuelMarble Size Guide →
FuelMarble S is a Japanese-engineered fuel efficiency device for passenger cars, delivery vans, and motorcycles. Drop it into your coolant reservoir and start saving on petrol or diesel — permanently. No tools. No mechanic. No engine modifications.
Verified by the Japan Fair Trade Commission (JFTC). Developed at the Kurume Institute of Technology over 10+ years. Over 180,000 units sold worldwide since 2002.
|
Up to 15% Fuel Efficiency Gain |
| 93% CO Reduction and 98% NOx Reduction |
| Zero Maintenance Required |
What FuelMarble S Delivers:
- Up to 15% fuel efficiency gain — government-certified testing
- 93% reduction in carbon monoxide (CO) emissions
- 98% reduction in NOx and hydrocarbons (HC)
- Drop-in coolant reservoir installation — under 60 seconds
- Zero maintenance — no refills, no servicing, no power source
- Compatible with petrol, diesel, and hybrid engines
- No engine modifications — does not void warranty
- Made in Japan — engineered to the highest precision standards
- For vehicles under 2 tons. Need a larger unit? See FuelMarble L
- How It Works (3 steps):
Installation — Under 2 Minutes:
-
Open the coolant reservoir under your bonnet — the translucent plastic tank, not the fuel tank.
-
Drop FuelMarble S inside and close the cap. No tools. No mechanic. No modifications.
-
Drive normally. Most drivers notice improved fuel economy after 150–200 km as the coolant system reaches full operating temperature.
See the full step-by-step installation guide
Verified Results
Real-World Test Results (independent, government-standard testing):
Honda Accord (Japan): 9.9 km/L → 12.6 km/L (+27.3%)
Volkswagen Golf (Japan): 8.5 km/L → 10.0 km/L (+17.6%)
Honda Freed (Indonesia): 16.83 km/L → 20.49 km/L (+21.7%)
Mercedes C-Class (China): 7.1 km/L → 9.1 km/L (+28.2%)
View all verified fuel efficiency test data
Product Specifications
| Product | FuelMarble S |
| Length | 130 mm |
| Diameter | 15 mm |
| Compatible with | Cars, vans (under 2 tons) |
| Fuel type | Petrol, diesel, hybrid |
| Installation | Coolant reservoir - drop-in, no tools required |
| Maintenance | None - permanent device |
| Country of manufacture | Japan |
| Shipping | Free UK delivery |
| Returns | 30-day return window |
Share
Frequently Asked Questions
What makes FuelMarble L different from FuelMarble S?
FuelMarble L is larger (220 mm vs 130 mm) and is designed for vehicles over 2 tons — including SUVs, HGVs, commercial fleets, and marine vessels. It delivers the same core fuel efficiency and emission reduction benefits as FuelMarble S, with the addition of DPF protection through cleaner, more complete combustion. For personal cars and delivery vans under 2 tons, see FuelMarble S
How does FuelMarble L protect the DPF?
FuelMarble L improves coolant performance, stabilising combustion temperatures so fuel burns more completely on every engine stroke. More complete combustion produces less unburned soot — which is the primary cause of DPF loading. With less soot entering the filter, passive regeneration cycles handle the load naturally, DPF blockages become less frequent, and costly forced regen events and filter replacements are significantly reduced.
How many units does my fleet vehicle need?
One FuelMarble L covers vehicles up to 4 tons. Vehicles between 4 and 13 tons require two units; vehicles over 13 tons (heavy haulage, industrial machinery, and large marine engines) require three units. See the size guide above for the full breakdown, or contact our team if you’re unsure.
Is FuelMarble L suitable for my HGV fleet?
Yes. FuelMarble L is designed specifically for heavy-duty diesel applications including HGVs, lorries, and commercial fleets. It works via the coolant system and requires no engine modification, making it compatible with Euro V, Euro VI, and Euro VII-compliant vehicles. For volume pricing and fleet deployment support,contact our teamor visit the fleet page
Can FuelMarble L be used in marine vessels?
Yes. FuelMarble L is compatible with marine engines running on heavy fuel oil (HFO) as well as diesel. Its coolant-based mechanism works independently of the fuel type. Commercial vessel operators typically require three or more units depending on engine size.Contact us for a vessel-specific recommendation.
What is the ROI for a large fleet deployment?
A 10-truck fleet running 100,000 miles per year at 8 MPG spends approximately £187,500 annually on diesel. At a conservative 15% efficiency gain, that fleet saves around £28,125 per year. The cost of 10 × FuelMarble L units is £5,190 — giving an estimated payback period of approximately 7 weeks. DPF protection savings (£1,000–£3,500 per avoided replacement) add further ROI on top. See the full fleet ROI breakdown