Treated fuel achieves cost and emissions savings

Even better, the benefits could be realised using existing vessels and standard fuels already in circulation: the results were achieved without engine modifications, hardware changes or alterations to fuel specifications; researchers said the efficiency gains were attributable solely to changes in fuel behaviour during combustion.

Rob Mortimer, CEO of the UK start-up Fuelre4m, says independent university testing at the National Technical University of Athens (NTUA) found that the technology delivered ‘measurable efficiency improivements’ in large marine engines operating on conventional marine fuels.

Carried out on a Caterpillar C9.3 diesel engine using an ABB-controlled dynamometer and independent, shaft-mounted torque measurement, the same fuel batch was used throughout the testing programme, with Fuelre4m’s treatment added directly to the service tank 12-15 hours before testing.

Cat C9.3 engines are designed for small to mid-sized commercial vessels, workboats and auxiliary power applications.

“In the most conservative fixed test condition, where shaft speed and load are deliberately held constant, fuel consumption was reduced by 3.5–6.7%, demonstrating that the fuel delivers more usable energy per unit consumed,” says Mortimer. “In real-world operation, where engines are not artificially constrained and can reduce load to achieve the same work, this improvement expresses as a materially larger efficiency gain, with independent testing showing propulsion efficiency improvements of up to 21%+.”

The findings have huge implications across the maritime sector, which consumes more than 200 million tonnes of fuel annually and continues to face rising pressure to reduce emissions while managing operating costs. Even incremental efficiency gains, if adopted at scale, could contribute to meaningful reductions in greenhouse gas emissions and fuel expenditure across global fleets.

The research comes as shipowners and operators assess compliance pathways under tightening international and regional emissions frameworks, including IMO decarbonisation targets. Rather than relying solely on newbuilds, alternative fuels or long-term infrastructure investments, the study points to a near-term option applicable to vessels currently in service.

“We were surprised by how consistent the efficiency improvements were across different operating conditions,” said George Papalambrou, Associate Professor at the National Technical University of Athens.

“Fuel remains one of the most significant cost components in maritime operations,” said Mortimer. “Reducing consumption delivers immediate economic and environmental benefits. What’s notable here is that these results were achieved using existing engines and fuels, allowing operators to act now rather than waiting for future solutions.”

The results were achieved without engine modifications, hardware changes, or alterations to fuel specifications. According to the researchers, the efficiency gains were attributable solely to changes in fuel behaviour during combustion.