HEDGE®-III Consortium
High-Efficiency Dilute
Gasoline Engine

Efficiency continues as the driving force globally.

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Efficiency continues as the driving force globally.

HEDGE-III will investigate solutions to the primary barriers to high efficiency in gasoline engines.

Click image for enlarged view 
HEDGE-III will investigate solutions to the primary barriers to high efficiency in gasoline engines.

image of HEDGE-III engine


The third High-Efficiency Dilute Gasoline Engine (HEDGE-III) program incorporates new and more aggressive efficiency, performance, and emissions goals that are in line with existing and potential future regulations and expectations. The overall goal is to develop the most cost-effective solutions possible for future gasoline engine applications. In addition, after eight years of research focused primarily on stoichiometric, high-EGR applications, the Consortium has begun to examine topics outside of cooled EGR that contribute to high-efficiency engine operation.

The emissions goals include the most stringent regulations in each of the three developed markets:

  • Asia
  • Europe
  • North America

HEDGE-III will target the low emission vehicle III (LEV III) standards and, for the first time, extensively investigate cold-start technologies and monitor particle mass/particle number (PM/PN) emissions on a regular basis. The efficiency goals include both practical thermal efficiency targets (in terms of BSFC goals on specific platforms) as well as overall thermal efficiency goals to achieve a "best in class" efficiency level.

HEDGE-III will continue the work performed in HEDGE-I and HEDGE-II and launch as a new four-year, annual renewal cooperative research program dedicated to the development of pre-competitive technologies that will be needed to cost-effectively achieve future emissions and fuel consumption requirements for world markets.


The objective of the HEDGE-III Consortium is to expand upon the work conducted in the HEDGE-I and HEDGE-II programs, thereby further developing efficiency improvements for gasoline engines. In HEDGE-III, SwRI will begin to shift the emphasis of the program to a more general examination of high-efficiency technologies, with less direct emphasis on cooled EGR. The HEDGE-III program will allow opportunities for member companies to jointly examine the high risk/high reward technologies that they might not otherwise consider, due to resource constraints that might be encountered by member companies individually pursuing the evaluation of these technologies.

Specific Goals

Based on the goals provided below, the goals for the HEDGE-III Consortium will be finalized during the initial program advisory committee (PAC) meeting in January/February 2013. Since the HEDGE-III Consortium is a continuously evolving research program, the goals of the Consortium will be modified on an infrequent basis, as results from the program and funding levels dictate.

Goals of the HEDGE-III Consortium

  • Efficiency
    • Light-duty (LD) engines
      • 42 percent at best brake thermal efficiency (BTE) point
    • Medium-duty/heavy-duty (MD/HD) engine
      • 46 percent at best BTE point (dual-fuel)
      • 44 percent at best BTE (SI/D-EGR™)
  • Emissions
    • Demonstrate SULEV potential on LD engines for:
      • PM
      • NOx
      • CO
      • HC
    • < US2010 or < Tier IV final emissions for MD/HD applications
  • Develop/demonstrate cold-start solutions for high EGR engines
  • Acceptable transient behavior (90 percent torque in < 3 seconds)
  • Develop more in-depth understanding of mechanisms to improve engine efficiency
  • Develop improved simulation tools for high dilution applications

Work Scope

The work scope of the HEDGE-III consortium will be based on the tasks required to meet the goals outlined above. To maintain flexibility in meeting the program goals and encourage continual innovation, SwRI and the HEDGE-III PAC will re-visit the work scope for each platform and the program as a whole on a regular basis. SwRI's intention is to create a work plan to meet the goals described above, while being flexible and dynamic enough to react to new developments.

HEDGE-III Consortium Membership & Benefits

  • Interested companies may join the HEDGE-III Consortium at any time during the four-year program.
  • Annual membership
    • $120,000 USD for OEMs
    • $70,000 USD for Suppliers
  • A yearly, renewable contract is offered to members.
  • The impact of the yearly contribution is multiplied by the number of participants.
  • One of SwRI's internal research programs, which involves control algorithms and modified combustion concepts, will be shared with Consortium members.
  • SwRI will aggressively pursue patent applications for technology developed during the HEDGE-III program.
  • Consortium participants will receive a royalty-free license to use the technology.

HEDGE-II Accomplishments

  • >44 percent BTE on a HD Dual-fuel engine that meets 2010 HD emissions standards for NOx and PM with no aftertreatment
  • >41 percent BTE on a LD engine
  • < 330 g/kWh on a light duty, stoichiometric engine at 2000 rpm/2 bar bmep
  • Significant improvement in EGR tolerance due to ignition and charge enhancement
  • Developed control scheme for high EGR applications

Related Terminology

high-efficiency dilute gasoline engine  •  engine performance  •  engine durability  •  emission requirements  •  motor vehicles  •  EPA  •  emission standards  •  lower emission levels  •  diesel engine technology  •  gasoline engine technology  •  light-duty vehicles  •  heavy-duty engine manufacturers  •  knock-resistant combustion chambers  •  high-energy ignition  •  high brake mean effective pressure  •  BMEP  •  exhaust gas recirculation  •  EGR  •  component suppliers  •  oil and fuel companies

Benefiting government, industry and the public through innovative science and technology
Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 9 technical divisions.