Passenger Vehicles
S
Best for sedans, SUVs, and small delivery vans.
Fleet Choice
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Made in Japan
FuelMarble L
Fuel Efficiency Device for Fleets, SUVs & Heavy Diesel
£519
20%
Fuel saving
DPF
Protection
93%
CO reduction
98%
NOx reduction
- ✓For SUVs, HGVs, fleets & heavy diesel
- ✓DPF protection — extends filter life
- ✓Drop-in coolant reservoir installation
- ✓No tools or mechanic required
- ✓Zero maintenance — permanent device
- ✓Diesel, HFO & petrol compatible
- ✓Free UK shipping
Check your vehicle size before ordering
Heavier vehicles may require 2 or 3 units of FuelMarble L. Vehicles over 4 tons need ×2 units; over 13 tons need ×3 units. See the size guide below ↓
Buy FuelMarble L — £519
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Fleet Enquiry / Volume Pricing🇯🇵Engineered and manufactured in Japan
✅Performance verified by government-certified testing
📦Free UK shipping. 30-day returns.
🔒Secure checkout via Shopify
Which size do I need?
FuelMarble size is determined by vehicle weight and engine demand. Use this guide to choose the right unit.
2-Ton Truck
L
Standard commercial light trucks.
4-Ton to 13-Ton
L
Install two L-Size units for engines in this class.
Over 13-Ton
L
Required for heavy haulage and industrial machinery.
Not sure? Contact our team and we will advise the correct product for your specific engine or application.
Product Features
Everything FuelMarble L Delivers
Eight core performance and protection benefits — all independently verified through government-certified testing.
✓
Up to 20% Fuel Efficiency Gain
The same government-certified efficiency gain as FuelMarble S, sized for vehicles between 2–4 tonnes GVW. Measurable savings from the first full tank of fuel.
✓
DPF Protection
Cleaner, more complete combustion reduces soot production — extending diesel particulate filter service life, reducing regeneration cycles, and protecting against costly DPF failure.
✓
CO Reduced by 93%
Independent test results confirm a 93% reduction in carbon monoxide output — a critical metric for fleet compliance with clean air zone regulations across UK cities.
✓
NOx Reduced by 98%
Near-complete elimination of nitrogen oxide emissions. FuelMarble L delivers exceptional NOx performance for heavy diesel engines operating in regulated environments.
✓
Drop-In Coolant Installation
FuelMarble L places directly into your vehicle's coolant reservoir. No tools, no mechanics, no modifications. Each unit installs in under 2 minutes per vehicle.
✓
Zero Maintenance Required
Once installed, FuelMarble L works permanently with no refills, no servicing, and no follow-up. Suitable for fleet vehicles covering hundreds of thousands of miles.
✓
Made in Japan
Engineered and manufactured in Japan using precision mineral technology. FuelMarble L uses a larger mineral array to match the demands of bigger coolant systems.
✓
Compatible with Heavy Fuel Oil
FuelMarble L's coolant-based mechanism works with both diesel and heavy fuel oil marine engines — making it suitable for commercial vessels and offshore applications.
Fleet ROI
The Numbers for a 10-Truck Deployment
FuelMarble L is built for scale. Here is what a typical fleet deployment looks like financially.
10 trucks at 100,000 miles/year£187,500/year in diesel
At 20% efficiency gain~£37,500 saved annually
Cost of 10 × FuelMarble L£5,190
Estimated payback~7 weeks
Based on 100,000 miles/year, 8 MPG, £1.50/litre diesel. Actual savings vary by vehicle and route.
DPF Protection
Protect Your Most Expensive Filter
Diesel particulate filter replacement costs £1,000–£3,500 per vehicle. Multiply that across a fleet with multiple premature failures per year, and DPF maintenance becomes a significant unplanned budget item.
FuelMarble L's cleaner combustion profile directly reduces the rate of DPF loading — extending service intervals and reducing the risk of blockage-related failure.
DPF cost savings per vehicle
£1,000–£3,500
Average DPF replacement cost. Avoiding one DPF failure per vehicle per year covers the cost of FuelMarble L many times over.
Specifications
FuelMarble L Product Details
ProductFuelMarble L
Price£519
Compatible withSUVs, HGVs, fleets, heavy diesel, marine
InstallationCoolant reservoir (drop-in)
Fuel compatibilityDiesel, HFO, petrol
DPF protectionIncluded
MaintenanceNone required
Country of manufactureJapan
ShippingFree UK delivery
Returns30-day return window
FAQs
Frequently Asked Questions
Also available
FuelMarble S
For personal cars & vans — £239
Reduce Your Fleet's Fuel Bill Today
Order FuelMarble L today. Fleet enquiries welcome. Free UK shipping. Secure Shopify checkout.