Saab has developed a new combustion control system which reduces fuel consumption while radically reducing exhaust emissions, without impairing engine performance. By mixing a large volume of exhaust gases into the combustion process, Saab’s fuel consumption can be reduced by up to 10 percent, and exhaust emissions lowered enough to comply with the California Ultra Low Emission Vehicle 2 (ULEV2) requirements, set to take effect in 2005. Compared to today’s Saab engines with equivalent performance, this will reduce the carbon monoxide and hydrocarbon emissions by almost half, and will cut the nitrogen oxide enissions by 75 percent.
The Saab Combustion Control (SCC) system is based on a combination of direct injection of gasoline, variable valve timing, and variable spark. Unlike the direct injection systems available on the market today, the SCC system puts to use the benefits of direct injection, but without disturbing the ideal fuel-to-fuel ratio necessary for a conventional three-way catalytic converter to perform satisfactorily.