Delphi's Diesel Engine Without Diesel Fuel

Hey, remember Delphi Powertrain? Once upon a time, it was part of GM, and it developed advanced concepts in — you guessed — powertrains. Since it failed to provide employment to enough grinning MBAs, however, it was shucked aside and cored-out like many other productive parts of the Artist Currently Known As Old General Motors.

Turns out, however, that the venture-capitalized folks working there are still making interesting things happen, and we aren’t talking about the V8-6-4 this time, either.

MIT’s Technology Review took a step away from their normal fare of celebrity gossip and short-fiction erotica today to report that Delphi has a single-cylinder compression-ignition engine up and running. This is not particularly interesting, since a fellow named Rudolf Diesel did it a long time ago without the aid of even a single iPad.

The jaw-dropper is this: this “diesel” engine uses gasoline. A direct-injection system pulses three precisely timed bursts of fuel during the compression-ignition cycle, and said fuel is reliably ignited without the hassles and inefficiencies of sparking.

Why’s this useful? Well, this engine could produce diesel-like fuel efficiency using plain gasoline, which can require up to 15% less crude oil per gallon to produce than diesel — and, not incidentally in these self-ashamed times, produces up to 15% less CO2 per gallon consumed. Also, and I am certain some diesel loyalist will firebomb my house for saying this, it seems to be generally acknowledged that the particulate emissions of diesel engines are both uniquely carcinogenic and difficult to trap. There’s also the fact that diesel fuel is sticky, doesn’t evaporate, gets all over your shoes, and is psychologically associated for some of us with the unique Interstate cultural phenomenon known as the “lot lizard”. But I digress.

Just like a diesel engine, this compression-ignition gasoline engine will no doubt require a variety of strategies to start and run correctly in cold weather. The Delphi engine already re-routes exhaust gas to re-heat the cylinder head in some circumstances. Glow plugs aren’t mentioned in the article but they are probably necessary. Diesel’s greatest cold-weather problem, however, is fuel composition and “gelling”, and gasoline is free from that worry.

Delphi’s scientist told MIT’s journalist that the engine could certainly be paired with a hybrid system to improve efficiency further, although “it’s not clear whether doing that would be worth the added cost.” Silly scientist! I bet he sits around at night and wonders whether the pedestal spoiler on the ’95 Grand Am actually reduces lift at high speeds. Nice to see there’s still some innocence in the world, huh?