“Our real in-depth knowledge of how to make high-pressure systems work was the key for us,” David Draper, Chief Engineer for Heavy Duty Systems at Delphi, told AEI at the IAA Commercial Vehicles event in Hanover, Germany, last week, regarding the use of advanced diesel technology to meet current and future global heavy-truck consumption and emissions goals.
“But nonetheless, we still had to provide an advanced common-rail capability,” Draper added. "We had to look at what our light- and medium-duty colleagues were doing with conventional common-rail and take it a step forward. We have a brand-new nozzle concept for Euro VI. We made a very clear decision about two years ago to change to something that was specific to make common-rail work better.”
With pressure from truck manufacturers and the European parliament to reduce fuel consumption by 20% by 2020, we asked Draper what contribution to that reduction he believed could be made by the fuel system.
“In terms of meeting a 20% reduction in CO2, I don’t honestly think that you’re going to go huge steps forward in efficiencies of fuel-injection systems,” he said. “To generate pressure, you need a certain amount of energy. If you’ve already reduced your parasitic losses to very low levels, I think the gains that you can make are quite small, and we are making sure that these Euro VI systems are at very high efficiency levels with extremely low leakages.”
“Our contribution to any massive reduction from an FIE [fuel injection equipment] viewpoint and vehicle economy isn’t there to be had, in my view,” Draper added. “It’s got to be about chassis, size of vehicle, rolling resistance, and air resistance. That’s where the 20% is; it’s not in the fuel-injection system. You might scrape another one to 1.5% maybe.”
“Alternatively, if the customers find that the new combustion regimes can offer digit percentage points increases in specific fuel consumption, we will just have to follow that in terms of the capability of our systems, not efficiency,” he said. “There are some things that we have already for upgrades to our Euro VI system that push the efficiency a little bit, but in terms of could it be measured on the vehicle in big numbers, the answer is ‘not really.’”