Ferrari is experimenting with ethanol to help its luxury sports cars produce lower emissions and improve fuel economy.
The sleek Ferrari F430 Spider Biofuel, with green stripes on its silver bodywork, consumes an E85 - 85% ethanol and 15% petrol- mix, a growing fuel blend in the US.
The carmaker says it produces 5% less carbon dioxide emissions and boosts horsepower by 10%.
It did not say how fuel consumption changed.
Ferrari's goal is to cut emissions by 40% by 2012.
It is showing the F430 Spider Biofuel at the Detroit Motor Show, along with two other models, including the 430 Scuderia that goes on sale this year.
The carmaker says global sales rose 14% last year to about 6 400 cars.