Undergrowth, dead trees, branches and bark that would otherwise be burned are converted to cellulosic ethanol at a pilot plant in Wyoming. This conversion process also produces lignin (the remaining wood fibers less their sugar) that is used to power the plant and to supply electricity to the power grid. Co-products of the ethanol conversion are used in composite woods, paints, cosmetics, livestock bedding, and livestock feed supplements.

"In terms of the Corvettes' LS7.R racing engines, the transition from the E10 that was used last season to the E85R that we are using this year was seamless," said Roger Allen, program manager for the Corvette C6.R. "We focused on making the engines as efficient as possible by recalibrating the ignition timing and the air-fuel ratio for E85R, and optimizing fuel cut-off under deceleration to reduce consumption."

Corvette Racing engineers have analyzed every aspect of the race cars to gain a competitive advantage on the race track. These enhancements will also play a critical role in the Green Challenge competition.

"Reducing losses caused by friction, aerodynamic drag, and rolling resistance improves overall efficiency," explained Wesoloski. "By minimizing these losses, more of the fuel's energy can be used to propel the race car.

"For example, Corvette Racing has worked with Mobil 1 to develop lubricants that reduce friction throughout the drivetrain – not just in the engine, but in the gearbox as well," he said. "We've changed from conventional steel wheel bearings to low-friction ceramic bearings – now when the car is on jackstands, you can turn the front wheels as easily as spinning a bicycle tire. The aerodynamic refinements that have been developed to increase top speed also reduce drag and the power that's required to push the car through the air. Michelin has an ongoing program to reduce the tires' rolling resistance while improving forward and lateral grip. Just as in a production vehicle, a number of small gains in a race car can add up to produce a significant improvement in overall efficiency."

On the highway and on the race track, the driver's right foot has an impact on fuel mileage. While winning the Green Challenge tops Corvette Racing's to-do list at Road Atlanta, Petit Le Mans is ultimately a race, not an economy run. The battle for the GT1 drivers championship is still being waged, with Johnny O'Connell and Jan Magnussen holding a 23-point lead over Oliver Gavin and Olivier Beretta with 55 points available in the final two races.

"One of the lessons we've learned in racing at Le Mans is that the drivers play a crucial role in fuel efficiency," Wesoloski said. "A driver can make a difference by how smoothly he makes the transition from braking to full-throttle acceleration on corner exit. Allowing the car to roll freely going into a corner before applying the brakes burns less fuel. With the telemetry and data acquisition that we have in GT1, our engineers can monitor fuel use throughout a stint, and the drivers can adjust their style to stretch the fuel load between pit stops." 10/2/2008