FEV, a leading developer of advanced powertrain and vehicle technologies, announced that it will exhibit a 2-step variable compression ratio (VCR) mechanism for the first time in the U.S. at the 2008 SAE World Congress starting today at the Cobo Center in Detroit.

The VCR mechanism was developed for use in both gasoline and diesel medium- and heavy-duty engines. The announcement was made by Gary Rogers, FEV, Inc. president and CEO.

"This mechanism has the potential to contribute greatly to overall vehicle fuel economy and the reduction of emissions," said Rogers. "The powertrain continues to evolve in response to the never-ending desire for higher efficiency. The need to explore renewable energy sources and fuels adds even greater demands for flexibility, while still focusing on reducing greenhouse gas emissions to the greatest extent possible. At FEV we are constantly looking at options that can be easily and cost effectively integrated into current technology to accelerate that evolution."

The 2-step VCR mechanism dynamically adjusts the center of the bore at the top end of the conrod, thereby achieving compression ratios of 14:1-17:1, depending on configuration, increasing engine efficiency and reducing NOx emissions. Key to the system is its ability to be integrated into existing engine designs due to its carryover piston and pin design. Other benefits derived from the ability to adjust the compression ratio include improved cold startability and the potential to optimize performance while utilizing alternative fuels.

The system currently supports peak cylinder pressures of 180 bar and is presently completing durability testing.