The net effect is that the rate of fuel consumption goes down. "We do that by reducing the negative work of the engine," Scuderi told us. "That's very simple to do, once you have a well run split-cycle. So our engine ends up being smaller but has higher power, better torque, and much better efficiency."
In simulations by Southwest Research Institute, Scuderi's split-cycle engine has performed well. When tested on several European economy-class vehicles (including an Audi A1 and a Citroen C1), the engine boosted fuel efficiency from an average of 53.5mpg to 65.4mpg, Scuderi said. It also lowered CO2 emissions from 104g/km to 85g/km.
Automakers are aware of the technology. "We are currently in discussions with about 15 of the 16 top auto manufacturers," Scuderi said. "Our first licensee will either be this year or early next year."
It's unclear how any of those companies would use the split-cycle engine, but it could easily work in conventionally powered vehicles, as well as in hybrids as a "range extender," he said. The engine could ultimately push the efficiency of so-called super-mini vehicles to 80mpg.
"Liquid fuel is still the best way to store energy," Scuderi said, comparing his engine's energy characteristics to those of an electric vehicle battery. "The amount of energy stored in a battery, even the largest lithium-ion battery, is still less than the energy that's available in a single gallon of gasoline."
Still, don't expect to see the Scuderi engine in a production vehicle anytime soon. Auto companies are notoriously slow to test and accept new technologies. And even when they do, they tend to work years ahead of their release dates.
"We know we have a long way to go," Scuderi said. "But we believe this engine will eventually provide a 50 percent increase" in fuel efficiency.