"The greatest trick the devil ever pulled off was to convince the world that gas engine a could act like a diesel."
Okay, maybe we changed this quote from "The Usual Suspects" just a bit, but it is something we're sure that some of you have thought at one time or another. What if you could take the upsides of a diesel engine and put them into a gasoline engine? Well Hyundai has decided to tackle this question and showed us what they came up with at a media preview event last week.
The engine is called GDCI or gasoline direct compression ignition. GDCI promises to return the fuel economy of a diesel, but come with better performance, a cheaper cost to manufacture, lower price of gasoline, and lower particulate emissions of a gasoline engine.
To understand how GDCI is able to pull this feat off, it would be a good idea to understand the difference between a gasoline and a diesel engine. A gas engine uses spark plugs during the combustion cycle to ignite the gasoline. A diesel engine doesn't use spark plugs at all. Instead, a diesel engine uses pressure to compress and ignite the diesel fuel.
GDCI takes the idea of using pressure to ignite the gasoline. In this case, the engine uses a high compression ratio - 14.8:1 - to cause the ignition of the fuel. The engine also features a set of exhaust valves that open twice per cycle to let heat in to help out in the combustion cycle.
Hyundai is also employing the use of twin-charging. A mechanical supercharger helps produce more low-end power, while a turbocharger handles the power on the high-end. Hyundai's manager of engine design and testing, Nayan Engineer (that is his real name), said the reason they are using twin-charging and not just turbocharging is that the GDCI engine doesn't produce enough exhaust flow to spool-up a turbocharger at low RPMs.
At the moment, Hyundai currently has GDCI engines running on engine dynos. The engines are 1.8L four-cylinders and are producing 180 horsepower at this time. Next year, the company plans to drop them into some vehicles to do some real-world testing.
Asked if GDCI engine would make it to the market, Engineer said that it will arrive in the "not too distant future." We take that to mean sometime within the next ten years or so.