Greentech company Sulnox says that Greek shipowner Spring Marine Group is expanding its use of Sulnox Eco across its entire fleet following two years of proven fuel savings and additional operational benefits.
Spring Marine, which operates a fleet of 28 tankers and bulk carriers, first introduced Sulnox Eco on a number of its vessels in 2023. Over two years the vessels have been fitted with Coriolis mass flow meters, torque meters and engine performance monitoring systems enabling evaluations to demonstrate consistent fuel savings averaging 5%, and specific fuel oil consumption (SFOC) reductions, alongside clear evidence of improved engine efficiency.
Notably, Spring Marine is extending use of Sulnox Eco to a number of vessels under charter. Whilst fuel costs are borne by the charterer, who benefits from reduced voyage costs and improved profit margins, Spring Marine also benefits from better charter rates, improved vessel energy efficiency operational indicator (EEOI) and asset value preservation. Aside from the fuel savings, operational and maintenance benefits have been reported by onboard crews, including:
- Cleaner combustion components across the engine with reduced carbon build-up on piston crowns, rings, and grooves
- Injectors in good, clean condition
- Purifiers operating efficiently with minimal sludge
- Consistently clean exhaust, with no visible black smoke
The Spring Marine fleet-wide rollout is said to represent another major supply arrangement and further validation for Sulnox Eco, generating significant repeat revenue for the company from a key customer in the influential Greek shipping sector. Based on current plans, Sulnox estimates annual Spring Marine product use could reach around 80,000 litres per annum as the rollout progresses.
Sulnox says it is currently engaged with around 75 shipping companies, with combined fleets of about 6,000 vessels. Sulnox Eco reduces emissions not only by lowering fuel consumption, but also by delivering complete combustion – significantly lowering particulate matter (black carbon), CO2 and other pollutants, and helping shipowners lower both environmental impact and carbon-related costs.
Capt George Chondronikolas, GM Spring Marine, said: “Sulnox Eco has become a valuable resource for our business on many levels. It noticeably reduces our fuel consumption and, two years after first adopting the product, results remain compelling. Critically, however, the positive impact on engine cleanliness helps improve our overall operational efficiency, while the lower emissions achieved are a great step towards our long-term decarbonisation objectives. We are delighted that all this has been delivered by a drop-in solution which required no capex or time in dry dock – unlike many other products in our vessel efficiency and decarbonisation initiatives.”
Ben Richardson, CEO Sulnox, added: “Spring Marine’s results once again demonstrate the long-term effectiveness of Sulnox Eco. Sustained improved performance over two years provides strong validation of our products and demonstrates the growing confidence that leading operators have in Sulnox to deliver real-world savings and emissions reduction – not only through lower fuel consumption but through more complete combustion, leading to lower emissions as the industry faces tightening carbon regulation and rising compliance costs.”
Image: Sulnox helps reduce black smoke due to incomplete combustion (source: Sulnox)



