Daimler AG has been awarded the coveted Steel Innovation Award 2015 in the category: "products made of steel".

The prestigious award of the German Steel Federation is bestowed every three years and this year honors the newly developed steel pistons for passenger car diesel engines, which boast significant CO₂ savings and high performance potential.

Two to four percent lower fuel consumption and CO₂ emissions – this is the overall noticeable balance of

Mercedes-Benz passenger car diesel engines, the first ever engines in the word equipped with innovative steel pistons in conjunction with lightweight aluminium housings. The new high-tech steel piston celebrated its world premiere in a production car last September - in the V6 diesel engine of the Mercedes-Benz E 350 BlueTEC.

Daimler admits that the combination of aluminium housing and steel pistons seems at first glance, to be a problematic combination, thanks to the fact that steel expands less when heated than aluminium does. It does not conduct heat as well and is also heavier. The Stuttgart engine designers have however, minted these apparent disadvantages into benefits. For example, the low expansion of steel through rising operating temperatures ensures a growing interplay between piston and aluminium housing, and reduces friction by 40 to 50 percent. The higher strength of steels allows, at the same time, a very compact designed, lightweight pistons, for even extra strength reserves. Finally, the lower thermal conductivity of steel leads to increased component temperatures, thus improving the thermodynamic efficiency with higher ignition performance and reduced burn time.

Mercedes-Benz has also completely redesigned the pistons used. The modern designed steel pistons used for the first time in the V6 diesel in the E 350 BlueTEC, come at series production in the aluminium crankcase with NANOSLIDE^® cylinder liner coating. These are high-tech versions, which are forged from high-grade strong steel.