We Have Ignition: Hyundai's Experimental Gas Engine Runs Without Spark Plugs

A gasoline engine with diesel-like thermal efficiency.

Things look familiar outside, assuming you’re accustomed to engines that are both turbo- and supercharged. Combustion engineers mounting a last stand against electric propulsion harbor bizarre fantasies. The gasoline guys dream of the diesel’s  potent torque curves and exemplary thermal efficiency. Diesel devotees yearn for cheaper fuel and relief from expensive injection systems and complex emissions controls. But what if both camps collaborated on one super engine combining the best of both technologies? You’d get what Hyundai and Delphi call Gasoline Direct-Injection Compression Ignition (GDCI): a gas engine needing no spark plugs. Engineers have been studying this alternative for more than a decade. GM and Honda both demonstrated cars powered by homogeneous-charge compression-ignition engines running on gasoline. More recently, Hyundai and Delphi advanced the cause by switching to stratified charge (a rich mixture in part of the cylinder) in a 180-hp 1.8-liter four-cylinder using auto ignition from idle to a 4500-rpm redline. When the study moves out of the lab into two test cars later this year, it should be clear whether the combination of diesel efficiency and gasoline con­ven­i­ence with in reach .