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In the first decade of the new millennium, the American automotive customer market trended toward larger family-sized vehicles. At the same time, an increased need to reduce energy consumption, as well as decreased vehicle emissions, was becoming imperative. As a result, the automotive and electronics industries, the U.S. and Canadian governments, and the academic community worked together to launch Challenge X: Crossover to Sustainable Mobility.

The groundbreaking four-year competition (2004-2008) gave 17 universities in North America an opportunity to participate in hands-on research and development with leading-edge automotive propulsion, fuels, materials, and emissions-control technologies.

During the competition, students were challenged to re-engineer a 2005 Chevrolet Equinox to minimize energy consumption, emissions, and greenhouse gases while maintaining or exceeding the stock vehicle’s utility and performance. Using a development process modeled after GM’s Vehicle Development Process, teams gained valuable experience in real-world engineering practices. Participating teams were provided with a variety of resources to help achieve their objectives, including technical support and mentoring from General Motors and other sponsors. Each team also received $10,000 in seed money and were eligible to receive additional production parts, software, and hardware from competition-level sponsors.

Year One (2004-2005) focused on modeling, simulation, and testing of the advanced powertrain and vehicle subsystems selected by each school. Students used computer-based math modeling tools to objectively compare and select the advanced technologies to be used for their overall design. Teams also developed and used rapid prototyping and hardware-in-the-loop (HIL) tools to validate their models and control systems. The Year One competition was held at GM University and GM’s Milford Proving Grounds, where teams showcased their design efforts.

During Year Two (2005-2006), teams developed and integrated their advanced powertrain and subsystems into the donated vehicle. This year was often dubbed the ‘mule’ vehicle build year since teams had to get to a 65% buy-off stage. The year-end competition was held at General Motors Desert Proving Grounds in Mesa, Arizona and featured an extensive set of vehicle dynamic events including braking, handling, acceleration, fuel economy, drive quality, and trailer towing performance. Teams were also judged through technical design presentations and written reports.

In Year Three (2006-2007), teams had to refine their advanced vehicles into a showroom-ready vehicle. At the end of the academic year, teams traveled to General Motors Milford Proving Grounds in Milford, Michigan for dynamic vehicle testing. Much like in Year Two, teams had the chance to compete in several dynamic events like braking, accelerating, dynamic handling, and drive quality. The awards ceremony was held at General Motors Renaissance Center in downtown Detroit, Michigan.

The fourth and final year of Challenge X (2007-2008) featured additional refinement, as well as expansive outreach and media efforts throughout the community. The year began with a road rally through Los Angeles and a ride and drive at the Electric Vehicle Symposium 23 in Anaheim, CA in November 2007. In addition, teams showed off their vehicles to Jay Leno at his garage in Burbank, CA. Teams then had several months to refine their vehicle before taking part in vehicle testing at the Old Bridge Township Raceway in Englishtown, New Jersey in May 2008. After testing, teams began a three-day East Coast Road Rally, which began in New York City with a media event. Teams then made a stop in Baltimore for an education day, and then concluded at the U.S. Department of Energy in Washington, D.C.

Throughout the four years, students developed a strong understanding of advanced vehicle technologies that prepare them to become highly skilled engineers in the automotive industry and remain competitive in the global marketplace.

Inovations & Hightlights

The teams in Challenge X employed many novel ideas, approaches, and technologies that (1) provided near-term and long-term solutions to significantly reduce well-to-wheel energy consumption, (2) reduce petroleum energy consumption and emissions, (3) significantly reduce criteria tailpipe and GHG emissions, and (4) increase pump-to-wheel fuel economy. All of the teams selected hybrid vehicle designs for their student-modified vehicles, spanning the gamut of parallel, through-the-road, and series hybrid electric vehicle. These vehicles employed state-of-the-art nickel metal-hydride and lithium-ion battery packs. A variety of advanced electric drive systems employed by the teams enabled the hybrid electric vehicle features, such as regenerative braking, high-load electric assist, and engine transient smoothing.

Engine selections were dominated by highly efficient diesels and turbocharged spark-ignited engines operating on biofuels such as ethanol and biodiesel. More advanced engines, such as highly diluted and boosted spark-ignition engines and hydrogen-assisted ultra-lean burn combustion strategies were also used.

  • Five teams included the use of hydrogen as a second fuel.
  • The University of California at Davis was the only team to use plug-in hybrid technology for the energy source for its Challenge X vehicle.
  • One team, the University of Waterloo, employed a fuel cell as its primary propulsion system.
  • West Virginia University and the University of Akron used ultracapacitors to source high levels of power for short periods of time and recapture energy from braking.
  • Several teams used the auxiliary power units from fuel cells to power air conditioning and other parasitic loads to aid in HEV propulsion.
  • Mississippi State University had a 48% improvement in fuel economy in Year Two.
  • Five teams, including Ohio State University and Virginia Tech, used belt alternator/starter technology for an electric performance assist in their vehicles.
  • University of Waterloo posted zero emissions in Year Four.
  • Utilizing Argonne National Laboratory’s GREET model, University of Wisconsin-Madison team demonstrated a 52% reduction in GHG emissions relative to production counterpart in 2007.
  • In Year Two, Virginia Tech achieved the lowest well-to-wheel petroleum energy usage, reducing its vehicle’s petroleum use by 77%.
  • Fourteen of the 17 vehicles were able to reduce greenhouse gas emissions in Year Two.
  • In Year Three, Penn State achieved 0.06 g/mi NOx emissions utilizing a downsized diesel engine and a Urea injection system (< Tier 2 Bin 5).
  • In 2008, Mississippi State University’s ¼ mile acceleration time was 1.6 seconds less than the production vehicle.
  • University of Waterloo competed successfully in every event as a fully functional fuel cell vehicle – a first for a fuel cell vehicle in advanced technology vehicle competitions.
  • The first ‘Outstanding Women in Engineering’ award was introduced in 2006.
  • University of Tulsa decreased well-to-wheel greenhouse gases by 41% in 2008.
  • 15 vehicles completed the 328 mile Road Rally in Year Four.
  • During the final year, Texas Tech achieved a 74% reduction in Petroleum Energy Use
  • The University of Texas at Austin was one of the first teams to include MP3 and GPS connectivity into their student-designed vehicle in 2008.

Universities Involved

Winners & Awards

Each year, university teams compete in a variety of static and dynamic events that range from oral presentations to on-road vehicle testing to communication and business tactics. These static and dynamic events are judged by industry sponsors and professionals, both throughout the year and in-person at the year-end competition.

Challenge X Media Coverage

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