Fuel-Saving Direct Injection Coming to Gas Engines

Siemens VDO has announced a new direct-injection technology for gasoline engines that cuts
fuel consumption by up to 20 percent. Researchers report that they developed the technology
using similar types of piezo injectors that already have been series-produced for diesel
engines for several years. The piezo ceramic components change length incredibly fast when
voltage is applied, thereby moving a valve needle that injects fuel in a fine spray at 200
bars of pressure in 0.0002 second. This is four to six times faster than the solenoid valve
injectors presently in use. Current gasoline-direct injection saves between 5-10 percent on
fuel, using special piston geometry to ignite the mixture; however, the disadvantage is
that it is not energy efficient. Piezo injectors can solve these problems with an extremely
precise series of injections that produce an ignitable fuel-air mixture directly at the
spark plug, exactly when needed. It may take until the year 2006 for a production engine.