OK, now this is intriguing, even if the article is from April(!?)…

New Car Engine Sends Shock Waves Through Auto Industry:

researchers at Michigan State University have built a prototype gasoline engine that requires no transmission, crankshaft, pistons, valves, fuel compression, cooling systems or fluids. Their so-called Wave Disk Generator could greatly improve the efficiency of gas-electric hybrid automobiles and potentially decrease auto emissions up to 90 percent when compared with conventional combustion engines.

The engine has a rotor that’s equipped with wave-like channels that trap and mix oxygen and fuel as the rotor spins. These central inlets are blocked off, building pressure within the chamber, causing a shock wave that ignites the compressed air and fuel to transmit energy.

The Wave Disk Generator uses 60 percent of its fuel for propulsion; standard car engines use just 15 percent. As a result, the generator is 3.5 times more fuel efficient than typical combustion engines.

Researchers estimate the new model could shave almost 1,000 pounds off a car’s weight currently taken up by conventional engine systems.

There’s also a minimal Wikipedia page about the invention.

Notice that the article says the team hopes to have a car-size, 25kW model built by the end of “the year”, which would be, well, right about now. But the Wikipedia article says they’re aiming for the end of 2013.

It’s worth pointing out that there’s quite the set of hurdles between “Hey! Look what I got to work in the lab!” and “It’s in mass production and you can buy one.” I wouldn’t be surprised, for example, to find out in time that this invention never makes it to market because the engine wears out after the equivalent of a few thousand miles of driving, or it’s really hard to make run over a useful range of RPMs, or it won’t work well in cold weather or with iffy gasoline quality, or who knows what else. This is in no way a criticism of the teams working on this particular project, merely a recognition of how perversely difficult it is to build general purpose engines for motor vehicles.

As another example, I remember reading articles about continuously variable transmissions a long time ago, probably in the mid to late 1970s. But they didn’t become a common item in mass market cars until the last few years. (Having said that,I’m sure someone will jump here with an example from the 80s or 90s to prove me wrong.)

I would love to see something like this clear all those hurdles and go into production; gasoline- or diesel-consuming vehicles are going to be around for a lot longer than we’d prefer, and we sure could use a vastly cleaner and more economical alternative engine become available.