Comment Re:Brazilian Ethanol [Re:Don't blame me] (Score 2, Informative) 894
Not exactly true. Most flex fuel vehicles are just the normal gasoline optimized engine with sufficient excess capacity in the fuel injector size and trim settings to allow the larger volume of ethanol needed for their operation. However, it is possible to optimize a flex fuel engine for ethanol fuels. Saab has done this for several years now:
http://www.greencar.com/articles/saab-9-5-biopower-gasoline-ethanol-flexfuel-vehicle.php
This Saab is a turbocharged engine and adjusts its turbo settings to provide more boost when it senses it is running on the much higher octane E-85 fuel...effectively increasing the compression ratio in the cylinder. First semester Thermodynamics tell you that the higher compression ratio offers more theoretical efficiency. This Saab puts out more horsepower and torque running on E-85 than on gas, and it gets approximately the same mileage in town and 15% better mileage on the highway.
http://www.greencar.com/articles/saab-9-5-biopower-gasoline-ethanol-flexfuel-vehicle.php
This Saab is a turbocharged engine and adjusts its turbo settings to provide more boost when it senses it is running on the much higher octane E-85 fuel...effectively increasing the compression ratio in the cylinder. First semester Thermodynamics tell you that the higher compression ratio offers more theoretical efficiency. This Saab puts out more horsepower and torque running on E-85 than on gas, and it gets approximately the same mileage in town and 15% better mileage on the highway.