THE COMPLICATED FUTURE OF OFF-HIGHWAY ENGINES

Developing an optimum engine is getting tricky now that the European Union has established a Stage V for off-highway engines, and the U.S. has not. What effect will this have on future engine designs?

The latest twist for providers of engines for off-highway use is the recently proposed Stage V emissions regulations covering European Union countries. EU regulators will limit the allowable particle number (PN) for the first time in off-highway equipment, as well as further reducing particle mass (PM) compared to Stage IV. The PN limit is proposed at 1×10¹²/kW·h. The regulations will not be finalized until January 2016 and the expected phase-in will start in 2019. Most expect the final limits to be as currently proposed.

The proposed Stage V regulations will have different impacts on different engine categories, Michael Franke, Director, Light-Duty Diesel and Commercial Engines for FEV North America, told Off-Highway Engineering. He also noted that besides reducing PM and PN for engines between 19 kW and 37 kW, Stage V also reduces NOx, HC, and CO limits. “Stage V is applicable over a wider range of engine outputs [than Stage IV],” he said. “It includes compression ignition engines below 19 kW and all engines above 560 kW.”