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FOR RELEASE: 2007-06-05

On Road Fuel Economy

• Photography

The purpose of the on-road energy use event is to determine the energy use and fuel economy of participant vehicles. Vehicles will be driven over a closed-loop road circuit with varying speeds, accelerations, and start/stops. The type of driving over the closed loop is designed to simulate real-world driving conditions.

The purpose of the On Road Fuel Economy event is to determine the amount of fuel energy that each competition vehicle uses over a set driving distance. Each team drives their vehicle on the same roads while following a set driving pattern of speeds, accelerations, and stops that represent a mix of city and highway driving. At the end of the event, the amount of fuel used by that vehicle over the entire drive cycle is divided by the distance driven which gives a fuel economy number in miles per gallon. However, since many of the teams are using alternative fuels other than gasoline like E85 ethanol (85% ethanol, 15% gasoline) and B20 biodiesel (20% biodiesel, 80% diesel) the energy content in one gallon of these fuels varies, and the teams cannot be compared against each other or against the stock vehicle equally.

So, each team’s measured fuel economy is instead calculated in miles per gallon gasoline equivalent (mpgge). Miles per gallon gasoline equivalent is simply a way of stating the vehicle’s fuel use (or energy use) in terms of equivalent miles per gallon, because consumers are familiar with those units. This calculation is carried out by taking the energy content of the volume of alternative fuel used and expressing that amount of energy is in gallons of gasoline to give a fuel economy measurement that is in miles per gallon gasoline equivalent (mpgge).

So far, X teams have completed the On Road Fuel Economy event, with X of the teams achieving higher fuel economy than the stock vehicle. Maybe include more details from competition, or an individual quote?

With recent increases in fuel prices, vehicle fuel economy is becoming more important to consumers. Technologies demonstrated in Challenge X, such as alternative fuels and hybrid vehicles, represent personal mobility solutions that can meet consumer expectations. Producing hybrid vehicles is one piece of GM’s three-part strategy to improve fuel economy and reduce vehicle emissions, along with improving the efficiency of the traditional internal combustion engine and developing hydrogen fuel cell vehicles.

Later this year, GM will launch hybrid versions of the Chevrolet Tahoe and GMC Yukon fullsize SUVs, which

The 2-mode hybrid technology in these buses has served as the starting point for GM’s co-development with DaimlerChrysler and BMW Group of the 2-mode hybrid system for passenger vehicles, that GM will launch later this year in the Chevrolet Tahoe and GMC Yukon fullsize SUVs, followed in 2008 by the Cadillac Escalade fullsize SUV, Saturn Vue Green Line compact SUV and the Chevrolet Silverado and GMC Sierra fullsize pickups.