An engine development company called the Scuderi Group recently announced progress in its effort to build an engine that can reduce fuel consumption by 25 to 36 percent compared to a conventional design. Such an improvement would be roughly equal to a 50 percent increase in fuel economy.

Sal Scuderi, says that nine major automotive companies have signed nondisclosure agreements that allow them access to detailed data about the engine. Scuderi says he is hopeful that at least one of the automakers will sign a licensing deal before the year is over. Historically, major automakers have been reluctant to license engine technology because they prefer to develop the engines themselves as the core technology of their products. But as pressure mounts to meet new fuel-economy regulations, automakers have become more interested in looking at outside technology.

Although Scuderi has built a prototype engine to demonstrate the basic design, the fuel savings figures are based not on the performance of the prototype but on computer simulations that compare the Scuderi engine to the conventional engine in a 2004 Chevrolet Cavalier, a vehicle for which extensive simulation data is publicly available, Scuderi says. Since 2004, automakers have introduced significant improvements to engines, but these generally improve fuel economy in the range of something like 20 percent, compared to the approximately 50 percent improvement the Scuderi simulations show.

There's a big difference, however, between simulation results and data from engines in actual vehicles, says Larry Rinek, a senior consultant with Frost and Sullivan, an analyst firm. "So far things are looking encouraging—but will they really meet the lofty claims?" he says. Automakers should wait to see data from an actual engine installed in a vehicle before they license the technology, he says.

A conventional engine uses a four stroke cycle: air is pulled into the chamber, the air is compressed, fuel is added and a spark ignites the mixture, and finally the combustion gases are forced out of the cylinder. In the Scuderi engine, known as a split-cycle engine, these functions are divided between two adjacent cylinders. One cylinder draws in air and compresses it. The compressed air moves through a tube into a second cylinder, where fuel is added and combustion occurs.

Splitting these functions gives engineers flexibility in how they design and control the engine. In the case of the Scuderi engine, there are two main changes from what happens in a conventional internal-combustion engine. The first is a change to when combustion occurs as the piston moves up and down in the cylinder. The second is the addition of a compressed-air storage tank.

Source: TechnologyReview