Federal-Mogul Corporation has developed a new coated piston for gasoline engines that combines the properties of low wear and low friction in a single application. The new EcoTough-coated piston offers superior wear resistance and reduces fuel consumption up to 0.8 percent, as well as reduced CO2 emissions, compared to conventional piston coatings. The EcoTough-coated piston is compatible with existing and advanced cylinder bore finishes and can be introduced seamlessly in volume engine production as a running change.
The key behind the EcoTough-coated piston technology is the composition of the coating, which is comprised of solid lubricants, including graphite, molybdenum disulfide (MoS2) and carbon fiber. In applications requiring additional protection, for example with a rough cylinder honing structure, the EcoTough-coated piston offers a greater coating thickness than pistons with conventional coatings. The technology suits high-volume manufacturing and is less sensitive to pre-treatment process variations, resulting in greater robustness and minimized dispersions in performance. The EcoTough-coated piston also fulfills the most stringent environmental standards and contains no toxic solvents.
“Federal-Mogul’s global strategy is to develop leading-edge technologies and innovative solutions that improve fuel economy, reduce emissions and enhance vehicle performance,” said Rainer Jueckstock, Federal-Mogul senior vice-president of Powertrain Energy. “EcoTough is a proven solution that will help OEMs meet the stringent regulatory requirements for their vehicles.”
Customer and governmental mandates to reduce CO2 emissions and fuel consumption makes the reduction of parasitic friction losses between the piston and the cylinder bore a priority for vehicle manufacturers. At the same time, the power output-per-liter of engine displacement is increasing as engines are downsized and boosted by turbo- or super-charging, subjecting pistons to higher mechanical and thermal loads.
In laboratory testing, EcoTough-coated pistons show an 18-per cent piston friction loss reduction and an improvement of up to three per cent in entire engine parasitic loss. Engine bench tests confirm a fuel economy benefit of 0.4 to 0.8 per cent in normal driving conditions. In wear resistance testing at full load and after 50 cold-start cycles, EcoTough-coated pistons demonstrate a major reduction in wear on the piston surfaces in contact with the cylinder.
“EcoTough offers vehicle manufacturers an attractive combination of benefits — a reduction in fuel consumption and CO2 emissions, coupled with improved wear resistance and straightforward implementation,” said Dr. Frank T.H. Doernenburg, Federal-Mogul’s director of technology, pistons and pins. EcoTough-coated pistons are currently in production, having recently been introduced on a high volume vehicle from a major European manufacturer.