Scuderi Group is one of a handful of companies seeking to break with the traditional design of the internal combustion engine in the name of fuel efficiency.

The company today announced results from a simulation using its namesake engine with a Nissan Sentra sedan that showed a 36 percent reduction in fuel consumption, the equivalent of a 54 percent improvement in miles per gallon. That same level of performance jump can be achieved with other cars, according to president Sal Scuderi.

The efficiency test, done in conjunction with applied research lab Southwest Research Institute, is a step in convincing major automakers to consider licensing the Scuderi engine. The company expects to license its engine design to an automaker in the second half of this year and go public in 2012, said Scuderi.

The Scuderi Engine improves fuel efficiency with a modified compression and combustion cycle, compressed air storage in a tank, and a turbo charger that allows for a smaller compression cylinder.

Internal combustion engines remain firmly rooted in the four-stroke and diesel engine designs developed in the late 19th century. But with government fuel efficiency mandates and concern over oil prices, there's interest percolating in alternative designs.

The Scuderi Engine, under development for about 10 years, uses three different techniques, including storing energy as compressed air, to improve on the four-stroke piston engine. Other companies, including EcoMotors, Achates Power, and Pinnacle Engines, are also working on efficiency and power improvements using an opposed-piston approach. These engines could be used in different types of vehicles and be combined with other efficiency techniques such as hybrids, aerodynamics, and lighter materials.

The Scuderi Engine began as an experiment to improve the thermodynamics of engines started by Sal Scuderi's father, Carmelo, when he was semi-retired from a career in engineering. Carmelo Scuderi died suddenly of a heart attack in 2002 shortly after the company was formed to pursue his design.

The company initially raised half of a million dollars and has since raised nearly $80 million in total from individual investors. Eleven automakers have signed nondisclosure agreements to examine the technology, according to Scuderi.

The Springfield, Mass.-based company has built one prototype engine on which it is running tests. The Nissan Sentra efficiency simulation was done by running it through one drive cycle over a few months and then simulating the efficiency gains over that same cycle, Scuderi said.

Air hybrid The Scuderi Group is seeking to license the fundamental design change Carmelo Scuderi originally sketched out, called the split-cycle design, along with two additions meant to improve efficiency further.

With the Scuderi Engine, there are two sets of paired cylinders, rather than four individual cylinders, with one pair dedicated to compressing air and the other to powering a car, Scuderi explained.

Combustion in a typical gasoline engine happens as a piston approaches the top of a cylinder. With the Scuderi Engine, it happens as the cylinder is on the down stroke, giving it more leverage on the crankshaft and helping the car accelerate efficiently, according to description in Technology Review. The design allows for fast combustion and high pressure in the compression cylinder, with the net effect being better fuel economy and reduction in air pollutants, according to the company.

The company improved on this design by adding an air tank to store compressed air in what it calls an air hybrid design. The compressed air tank, which could be placed anywhere in a vehicle, effectively acts to store energy by capturing energy as the car slows down. It then delivers compressed air to the engine during acceleration, Scuderi explained.

Its third technique is to add a turbo charger to better control the internal air pressure in the engine without adding to the size of the cylinders, thus saving weight compared to traditional turbos, Scuderi said. The company expects it can gain further efficiencies from what it has achieved so far, he added.

"When you add the three pieces of technology, you have this combination that really is new engine technology," he said. "Once you have the split-cycle engine, adding the air tank and turbo are easy and cost effective."

Even with the gains in efficiency, though, it's not clear that the Scuderi Engine will make out of the lab and into autos. Large automakers typically control engine designs, which are usually developed internally.

Scuderi said that the company is running tests on cars from a number of automakers, which indicates some interest. It published the Nissan Sentra results because tests for individual automakers can't be made public.

Working on the initial idea as a business for nearly ten years has been challenging, even to get the attention of automakers and be taken seriously.

"If you told me back in 2002 when we decided to push forward with this that we would have to raise $80 million and take 10 years to get to this point, I would've said you can't make it and probably wouldn't have tried," Scuderi said. "Fortunately for us, the technology has always progressed."