Does FuelMarble work if my vehicle already uses coolant additives?

Yes — and the laboratory data confirms it. Professor Watanabe's research at Kurume Institute of Technology tested FuelMarble specifically inside a 30% coolant additive solution, the same concentration used in most commercial trucks and buses. Two tests were run. Test 1 (pH stability): pH remained completely stable — FuelMarble does not react with or cancel out existing coolant additives. Test 2 (surface tension): FuelMarble reduced surface tension by a further 2% on top of what the coolant additive was already achieving, measured across 25–70°C. Because FuelMarble works physically — not chemically — it adds its effect on top of whatever your existing additives are already doing. Notably, virtually all vehicles in Japan run coolant additives as standard, meaning the real-world performance data — including the Yamanashi Kotsu bus trial — was collected with coolant additives already present in the system. The results are not from pure-water conditions.

Which Vehicles It Works On

Which vehicles is FuelMarble compatible with?

Q: Which vehicles are compatible with FuelMarble?

FuelMarble is compatible with any vehicle that has a coolant reservoir connected to an internal combustion engine: petrol and diesel passenger cars, SUVs, motorcycles, delivery vans, haulage trucks, agricultural machinery, generators, boilers, and marine vessels. Choose FuelMarble S for passenger vehicles and light commercial; choose FuelMarble L (or multiples) for heavier vehicles.

FuelMarble works in any vehicle with a coolant reservoir connected to an internal combustion engine — petrol or diesel. This is the compatibility and sizing companion to our overview of how FuelMarble's coolant technology works: which vehicle classes it fits, how many units by weight, and the independent coolant-system safety data.

Compatibility

Compatible vehicle types

FuelMarble works in any vehicle with a coolant reservoir connected to an internal combustion engine — petrol or diesel.

Personal Cars & Sedans

SUVs & MPVs

Buses & Coaches

Delivery Vans

Haulage Trucks

Agricultural Machinery

Marine Vessels

Unit sizing by vehicle weight

Vehicle Class	Example Models	Approx. GVWR	SKU	Units
Motorcycles & small cars	Honda Civic, Toyota Yaris, VW Polo	Under 1.5t (≈ under 3,360 lbs)	FuelMarble S	1
Family cars, SUVs & MPVs	Ford Focus, BMW 3 Series, Toyota RAV4	1.5–2t (≈ 3,360–4,480 lbs)	FuelMarble S	1
Large SUVs & pickup trucks	Land Rover Defender, Toyota Hilux	2–3t (≈ 4,480–6,720 lbs)	FuelMarble L	1
Light commercial vans	Ford Transit, Mercedes Sprinter, VW Crafter	3–4t (≈ 6,720–8,960 lbs)	FuelMarble L	1
Medium trucks	Isuzu NPR, MAN TGL, DAF LF	4–13t (≈ 8,960–29,120 lbs)	FuelMarble L	2
Heavy trucks & HGVs	Volvo FM, DAF XF, Scania R, MAN TGX	13t+ (≈ over 29,120 lbs)	FuelMarble L	3

GVWR (Gross Vehicle Weight Rating) figures are indicative; pound equivalents follow your region's ton. Multiple units share one coolant circuit — they do not require separate reservoirs.

FuelMarble S

Get FuelMarble S for cars and vans under 2 tonnes.

FuelMarble L

Get FuelMarble L for HGVs, buses, and commercial vehicles.

Running more than a handful of vehicles? See fleet-wide deployment for UK operators.

Coolant System Safety

Coolant System Safety & Compatibility

Independent laboratory testing confirms FuelMarble has no adverse effect on standard automotive coolant — pH stays neutral, viscosity is unchanged, and oxidation resistance doubles.

Tested in 30% ethylene glycol solution (standard automotive antifreeze concentration) — Watanabe et al., SAE Japan 2008

Property	Result	Conclusion
pH	Peaks at 7.4 at 80°C	Neutral throughout 30–90°C operating range. No acidification risk.
Viscosity change	< 0.7% over 14 days	Negligible. No impact on water pump performance.
ORP (Oxidation Resistance)	Doubles from 345 mV → 692 mV	Treated coolant actively resists oxidation and scale. Extends cooling system lifespan.
Surface tension	Reduced ~2% (20–70°C)	Sustained reduction across full operating temperature range.
Heavy metals	None leachable	Inert sintered glass. No solvents.

Compatible with standard coolant inhibitors. For a full explanation of how FuelMarble differs chemically from fuel additives — including why it carries zero DPF risk — see our dedicated guide.

Lab Research — Prof. Watanabe, Kurume Institute of Technology

What if my fleet already uses coolant additives?

FuelMarble delivers 7–10% fuel efficiency improvement even when installed in a coolant system that already contains liquid coolant additives. No reduction in performance. No chemical conflict.

Test 1 — pH Stability

FuelMarble was tested inside a 30% coolant solution — the same concentration used in most commercial trucks and buses. pH remained stable throughout. The coolant chemistry was not disrupted. FuelMarble does not interfere with existing coolant additives.

Test 2 — Surface Tension

FuelMarble was tested inside 30% coolant solution across 25–70°C. Surface tension dropped by a further 2% compared to coolant alone — confirming FuelMarble's core mechanism continues to work even with coolant additives already present.

Japan context: Virtually all vehicles in Japan already run coolant additives as standard. This means the performance data — including the Yamanashi Kotsu bus trial results — was collected under real-world conditions with coolant additives already in the system. The results are not from pure-water conditions. FuelMarble's verified 7–10% improvement is what you can expect on top of your existing additives, not instead of them.

Still weighing it up? See answers to common compatibility questions — including winter performance and how it affects horsepower.

FAQ

Frequently Asked Questions

Find the right unit for your vehicle

FuelMarble S FuelMarble L