Supercritical Fuel Injection Development Promises More Efficient Combustion

It seems political forces are pushing us towards EVs long before EVs are ready for prime time. “California has enormous power over the future of vehicles in this country,” and California regulators want to dump carbon, Tom Baloga, of BMW of North America told a packed audience at a session on EVs at an MIT energy conference March 6th. Thus, we have the Tesla, and the Fisker Karma, and the Leaf and the Volt are due out this year, and I don’t know anyone who wants to buy one, do you?

But for all their limitations, EVs have one major advantage: electricity is cheap compared to gasoline. But a new development may change that equation. A company called Transonic Combustion, based in Camarillo, CA has developed a supercritical fuel injection system that could boost the fuel economy of ICE by 50-75%, and it is working with two unnamed Asian OEMs, as well as one Euro, and one US to get these things onto cars in showrooms for model year 2014. In fact, a Prius-equivalent in-size-and-mass diesel test car achieved 64 mpg highway (EPA cycle), making the 48 mpg highway (EPA) Prius look thirsty by comparison (your mileage may vary!). The VC firms Venrock and Khosla Ventures have invested.

A “supercritical” state has unusual properties that enable short ignition delay, faster, more uniform and complete combustion that minimizes crevice burn and partial combustion near the cylinder walls, and that reduces the heat losses that waste copious energy in conventional engines. The system can also run with the air intake open at speeds where it would normally be throttled, thinning the air/fuel mix down to 80:1. The result of all this: cruising steadily at 50 mph yielded nearly 100 mpg in the test car, Mike Rocke, Transonic’s VP of business development told Technology Review.

The fuel, which can be any of a number of hydrocarbons (gasoline, diesel, biodiesel, vegetable oil, heptane, and ethanol have all been used successfully) must be heated and pressurized prior to injection into the combustion chamber. The necessary high technology would add about $1,500 to the cost of an engine, according to the company, but it is simple and light weight compared to the batteries and software that make a hybrid.

This doesn’t necessarily mean that some amazing fuel cell or battery development won’t come along and take the wind back out of internal combustion’s sails. But it’s also conceivable, even if that happens, that some other development in ICE might boost gas mileage well into triple digits. The bottom line: predicting technological developments is dicey. Politicians listen up: if you want to reduce carbon emissions, tax carbon. If you want to throttle the river of oil money flowing to OPEC, tax oil. But don’t try to micromanage technological development because you are likely to waste money on the wrong technology. I’m talking to you, Metropolitan Washington Council ofGovernments: If you want to encourage fuel efficiency with the HOV lanes, let single passenger cars on the HOV lanes during rush hour based on fuel mileage, or perhaps carbon mileage, but end that stupid break for hybrids. Some of them, like the Chevy Silverado, get pathetic mileage.