Fuel Economy and Emissions of the Ethanol-Optimized Saab 9-5 Biopower

Saab Automobile recently released the BioPower engines, advertised to use increased turbocharger boost and spark advance on ethanol fuel to enhance performance. Specifications for the 2.0 liter turbocharged engine in the Saab 9-5 Biopower 2.0t report 150 hp (112 kW) on gasoline and a 20% increase to 180 hp (134 kW) on E85 (nominally 85% ethanol, 15% gasoline). While FFVs sold in the U.S. must be emissions certified on Federal Certification Gasoline as well as on E85, the European regulations only require certification on gasoline. Owing to renewed and growing interest in increased ethanol utilization in the U.S., a European-specification 2007 Saab 9-5 Biopower 2.0t was acquired by the Department of Energy and Oak Ridge National Laboratory (ORNL) for benchmark evaluations. Results show that the vehicle’s gasoline equivalent fuel economy on the Federal Test Procedure (FTP) and the Highway Fuel Economy Test (HFET) are on par with similar U.S.-legal flex-fuel vehicles. Regulated and unregulated emissions measurements on the FTP and the US06 aggressive driving test (part of the supplemental FTP) show that despite the lack of any certification testing requirement in Europe on E85 or on the U.S. cycles, the vehicle is within Tier 2, Bin 5 emissions levels (note that full useful life emissions have not been measured) on the FTP, and also within the 4000 mile (6400 km) US06 emissions limits. Emissions of hydrocarbon-based hazardous air pollutants are higher on Federal Certification Gasoline while ethanol and aldehyde emissions are higher on ethanol fuel. The advertised power increase on E85 was confirmed through acceleration tests on the chassis dynamometer as well as on-road.