As global energy demand grows, America needs to keep innovating. Our nation is prospering, and a big part of that is the progress we’ve made in tapping our diverse wealth of domestic energy resources to keep the lights on, power industry, and fuel cars and trucks. New energy options can create jobs, boost the economy, provide affordable options for consumers, bolster global competitiveness, and improve national security.  Access to efficient and affordable transportation options will enhance economic growth.  There is great opportunity for American industry to develop fuel and engine technologies in tandem to achieve significant efficiency gains, and Co-Optimization of Fuels & Engines (Co-Optima)  is creating the science base to enable such development.

The Department of Energy (DOE) has brought together some of the nation’s brightest scientific minds to accelerate domestic innovation and create new opportunities in the automotive and fuel industries. DOE’s Office of Energy Efficiency and Renewable Energy (EERE) is working with researchers from nine national laboratories and thirteen universities on Co-Optima, exploring fuel and engine innovations that work together to maximize the performance and efficiency of petroleum-fueled vehicles.  This widespread collaboration, helmed by DOE’s Vehicle Technologies Office (VTO) and Bioenergy Technologies Office (BETO) leverages synergies across the national lab and university systems to amplify research efficiencies and innovation, and also involves ongoing engagement with representatives from a wide range of industries and government agencies.

Breakthrough Fuels-Engines R&D Offers Dramatic Boost in Fuel Savings, Economy, and Energy Security

While advanced engine designs are being introduced commercially, they are limited by current fuels. The Co-Optima initiative seeks to identify the optimal combinations of engine and fuel technologies to maximize practical efficiency while achieving emissions standards. This new way of thinking about fuels, as design variables rather than constraints to engine designs, could revolutionize the entire on-road fleet, from light-duty passenger cars to heavy-duty freight trucks. The outcomes of Co-Optima are certain to benefit both American citizens and businesses at the pump, with projections of an additional 10% improvement in 2030 passenger vehicle fuel economy.

Much of the Co-Optima research is focused on identifying promising fuel components known as blendstocks, which can be produced from a wide spectrum of domestic resources, including natural gas, petroleum―or domestic biomass. Bio-derived blendstocks can be produced from a variety of renewable, non-food, domestic biomass resources, such as forestry and agricultural waste.

Co-Optima researchers have identified eight representative high-octane blendstocks across five chemical groups that offer the greatest promise of delivering high efficiency and performance when combined with petroleum-based fuel in optimized engines. Researchers have shown that looking at fuel properties in a holistic way is key to reclaiming some of the efficiency left on the table from conventional fuels.  The Co-Optima engine efficiency merit function formalizes this approach by relating fuel properties to efficiency at a higher fidelity and inclusive of more fuel property data than ever before. The merit function has the potential to serve as the foundation for more robust fuel specifications that can explicitly include efficiency potential of different fuels. The science underlying the merit function, and the development of a fuel property database, has expanded the way in which researchers think and talk about fuels.

In addition to researchers’ work in the lab, Co-Optima analysts are developing a comprehensive understanding of the cost, benefits, air quality implications, and tradeoffs involved in producing these blendstocks from domestic biomass. Ultimately, this early-stage R&D will provide refiners with greater flexibility in delivering fuels needed to put the most efficient and high-performance cars and trucks on the road.

Even though the team is focused on solutions that are compatible with the existing trillion dollars’ worth of U.S. fuel infrastructure, these groundbreaking changes present researchers with a series of herculean tasks. Is it worth the effort? With the possibility of billions of dollars saved annually for consumers and businesses and 25 billion gallons a year of domestically sourced biofuel supporting new jobs for American workers, the payoff of a stronger economy and a more secure nation seem undeniable.


Michael Berube
Michael Berube oversees EERE’s Sustainable Transportation & Fuels sector. This portfolio focuses on research and development to increase access to domestic, clean transportation fuels and improve the energy efficiency, convenience, and affordability of transporting people and goods.
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Jonathan Male
Dr. Jonathan Male is the former director for the Bioenergy Technologies Office. In this role, he led the Office’s work to lower costs, reduce technical risk, and accelerate deployment of bioenergy and renewable chemicals technologies.
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