Transonic Supercritical Fuel Injection is another technical advancement for the internal combustion engine that shows rather startling gains in efficiency, 50 to 75 percent! "A test vehicle the size and weight of a Toyota Prius (but without hybrid propulsion) showed 64 miles per gallon for highway driving." That beats the hybrid. Transonic Combustion, the company working on this, has a test vehicle in the lab that is getting 98 mpg running at a steady 50 mph.
“A supercritical fluid is basically a fourth state of matter that’s part way between a gas and liquid,” said Michael Frick, Vice President for Engineering. A substance goes supercritical when it is heated beyond a certain thermodynamic critical point so that it refuses to liquefy no matter how much pressure is applied.
The injection systems can be integrated into modern high compression engines which means manufacturers don't need to develop entirely new drivetrains.
In laboratory tests on modern engine architectures, our technology has successfully run on gasoline, diesel, biodiesel, heptane, ethanol, and vegetable oil. Recently our engineers achieved seamless operation switching from several different fuels on one of our customer’s engines
TSCi Fuel Injection achieves lean combustion and super efficiency by running gasoline, diesel, and advanced bio-renewable fuels on modern diesel engine architectures. Supercritical fluids have unusual physical properties that Transonic is harnessing for internal combustion engine efficiency. Supercritical fuel injection facilitates short ignition delay and fast combustion, precisely controls the combustion that minimizes crevice burn and partial combustion near the cylinder walls, and prevents droplet diffusion burn.
The supercritical fuel mixes very rapidly with the intake air which allows better control of the location and timing of the combustion process. This system allows extremely lean combustion (up to 80:1 air-to-fuel ratios at cruise) extracting far more energy from any given amount of fuel, you get much higher mileage and lower emissions, too.
Every time we see a new electric drivetrain, along comes a dramatic improvement in the internal combustion engine. This isn't something you'll be able to hook up to some 50 year old engine, but it shows the modern ICE still has amazing opportunities for improvement. Very cool.