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Peugeot Citroën and Bekaert DLC Coatings Explore New Ways to go Green
PSA Group tests prove Bekaert DLC coatings can reduce engine emissions
The PSA Group (Peugeot Société Anonyme) and Bekaert are working together to make tomorrow’s engines more fuel efficient and more environmentally friendly.
Test Program Established
Two years ago a cooperative test program was established between PSA, the manufacturer of Peugeot Citroen automobiles, and Bekaert to measure the impact of diamond-like carbon (DLC) coatings on the frictional behavior of certain components within the valve train of a production engine. For this purpose, the components were coated with Bekaert’s Dylyn® Plus, a member of the company’s DLC family of coatings specifically aimed at high-volume automotive applications.
The test engine was a four-cylinder, 1.6-liter gas engine currently used by PSA. Bekaert coated certain components within the valve train assembly with a Dylyn® Plus DLC coating. Tests were then conducted on an electrically driven test rig. Hydraulic and mechanical tappets were tested over a wide temperature range (20°C to 120°C) in order to study the behavior in different conditions and to quantify the results.
Moment of Truth
It quickly became clear that the DLC coatings were a big benefit to the engine’s performance. The gains were very important at both low RPMs and at low temperatures, which corresponds with the operating conditions of city driving. On engine start up there is an immediate 20 percent gain - even at low temperatures - which increases to over 30 percent at normal operating temperatures. This means that in typical city driving, where most drivers do not exceed 3,000 RPMs (the typical urban range is 700-2,800 RPMs), a reduction of between 25 percent to 35 percent in friction loss is expected.
Mark Boghe, Bekaert’s DLC product market manager automotive/racing worldwide, said: “The PSA Group estimates that the overall fuel consumption is reduced by 1 to 2 percent, implying an estimated saving of 2-3g/km of carbon dioxide for a small engine. When you multiply this savings by the number of cars on the road, it clearly illustrates the importance of these results.”
Market indicators show that the benefits of DLC valve train coatings will be mostly visible in small gas-engined cars. Several engine manufacturers are developing small three-cylinder gas engines for smaller cars typically used in an urban environment.
For more information about Bekaert's DLC coatings, visit www.bekaert.com.
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