With a system that continuously cleans the lubricant in an engine, the frequency of oil changes can be cut dramatically.

Most car owners regularly leave their vehicles for service to keep them in good running condition. New cars can usually get away without unexpected repairs, but an aging car can be hard on your wallet. Regular oil changes can push back the day when crucial parts begin to fail, because all machinery needs particle-free motor oil or hydraulic fluid to reduce friction.

Oil captures fuel residues, metal particles and waste products, and standard oil filters won’t catch anything smaller than about 35 microns. This is why both oil and filter need replacement after a certain number of miles or operating hours. In Sweden alone, about 115 million liters of engine and hydraulic oil are consumed each year – and producing, transporting, replacing and disposing of all that oil costs some USD 800 million. Environmental impacts occur at several points in the chain – particularly greenhouse gas emissions – and there are substantial risks associated with management of waste oil.

The Swedish company Clean Oil Technology (COT) has developed a patented technology for continuous cleaning of oil while the engine is in operation. The system complements existing oil filters and gives the oil much longer service life. It’s the first system of its kind that reduces fuel dilution in motor oils – a particularly common problem with alternative fuels such as biodiesel, ethanol and biogas.

600,000 kilometers between oil changes

Under normal conditions, driving a bus 600,000 kilometers without an oil change would be tough – if not impossible – for any engine. But COT did just that in a marathon trial lasting several years, after installing its Oil Refiner SystemTM in a Scania bus operated by Sven Karlsson’s Trafik AB. The bus rolled on, kilometer after kilometer, while technicians closely monitored oil quality. After 600,000 kilometers, laboratory tests showed that the quality of the oil and additives remained high. The engine’s stock full-flow filter and the filter element in the COT system were replaced regularly. About a dozen oil changes were skipped, reducing oil consumption by some 300 liters during the test period.

“We are naturally delighted that our environmental technology works this well for such a long time,” says Göran Fredriksson, head of marketing at COT. “But manufacturers still specify the service schedule, even if the system allows for two to three times longer service intervals than normal. Longer intervals and less downtime are important for auto manufacturers and their customers alike. Our technology improves economy while reducing engine wear and environmental impacts. We help manufacturers and their customers to keep their environmental promises.”

Dirty oil damages motors

Filter uni

As oil circulates in an engine or any other machine, its lubricating functions break down from exposure to high temperatures, carbon byproducts, wear, soot and dirt particles, water, fuel and glycol. A full-flow filter can capture relatively large particles, reducing wear on the engine, but the oil still eventually gets dirty. Gear boxes, mechanical equipment and hydraulic systems have the same problem; eventually the oil is so polluted that it loses its lubricating properties and must be replaced. But waste products remain in the system even after an oil change, and the new oil is immediately contaminated. Since most engines are running much of the time on dirty oil, the interval between oil changes is in effect a compromise between tolerance for grit in the engine and the disadvantages of frequent oil changes.

Biofuels such as ethanol or biogas cause an increase in “fuel dilution,” or glycol contamination, of engine oil. Manufacturers recommend much shorter oil change intervals for these vehicles than for gasoline or diesel engines.

Continuous oil purification

Clean Oil Technology has developed a system for continuous cleaning of oil during operation. The COT Oil Refiner SystemTM is installed in parallel to the regular engine lubrication systems, purifying the oil with a low flow that has no effect on the engine oil pressure. The equipment complements the engine’s regular cleaning without affecting any other functions apart from reducing the burden on the stock filters.

Vaporization unit

The system includes two components:

  • A device that filters out particles larger than one micron (1/1000 mm), as well as water. The filter, which consists of a unique textile core with excellent separation characteristics, is replaced during regular maintenance.
  • A vaporization unit that removes volatile contaminants such as residual fuel and other hydrocarbons, antifreeze, water and acids. The process involves projecting oil projected on a surface heated to a precise temperature controlled by semiconductor technology without with no thermostat or other regulation.

Patented technology

  • A supplier to OEM manufacturers, COT focuses its marketing activities in three segments:
  • Vehicles – Trucks, buses and cars. The company sells to a number of bus transportation operators through cooperation with Volvo Buses and Volvo Trucks.
  • Heavy Duty – Construction equipment, forestry machinery, container handling and industrial applications. Hüllert Machine, an importer of Merlo telescopic handlers from Italy, equips the machines with the COT system.
  • Marine – The company sees great potential in the market for engines and equipment on board ships and oil platforms, not least because the marine environment imposes particular requirements on reliability and short thresholds for oil change frequency.

The original patents for the technology were acquired in 2000. After extensive development work, patent protection was significantly extended between 2005 and 2010.

Article published in March 2011