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About Us

Company profile 

Engine, Fuel, and Emissions Engineering, Inc. (EF&EE) specializes in reciprocating engine emissions and emissions control. We build, sell, and maintain advanced emission-control systems, including Compact SCR™ technology for gaseous-fueled and diesel engines. SCR, or selective catalytic reduction technology, reduces emissions from diesel, biogas, and natural-gas engines.

Combined with our Optimin™ self-tuning technology, the Compact SCR™ system enables natural gas and biogas engines to meet California's strictest emission standards. Compact SCR™ systems fitted to the diesel engines of the San Francisco-based ferries Gemini, Pisces, Taurus, and Scorpio reduced their emissions of oxides of nitrogen (NOx) and particulate matter (PM) by 97 percent and 60 percent, respectively, winning Gemini the distinction of being “the most environmentally friendly ferry in the nation.” 

EF&EE conceived and developed the RAVEM portable emissions measurement system for laboratory-grade emission measurements (including PM) under field conditions. We sell custom-built RAVEM systems for laboratory and field use, and use our own RAVEM to perform on-board and on-site emission measurements on engines, ranging from automobiles to container ships. 

EF&EE was founded in 1990 and incorporated as a California corporation in 1992. The company is privately held and more than 90 percent employee-owned.

About Us

Mission statement

At  EF&EE, our mission is to support the worldwide transition to an environmentally sustainable society by providing innovative technology, reliable products, and accurate information.


Since the company’s inception, EF&EE founder Christopher Weaver, P.E., has served as company president and been responsible for EF&EE's engineering work. Mr. Weaver is an automotive engineer with more than 25 years of experience in internal combustion engine technology, fuels, combustion, emissions, and emission controls. His work has focused on vehicle emissions measurement, and alternative fuels such as natural gas and ethanol, and post-combustion emission control systems such as diesel particulate filters and SCR. 

As a consultant to the U.S. Environmental Protection Agency in the 1980s and 1990s, Mr. Weaver played a key role in the establishment of heavy-duty diesel emissions standards, sulfur and aromatic limits on diesel fuel, and the phase-out of leaded gasoline in the United States. A study of emissions control for off-highway vehicles led to the inclusion of regulatory authority for such vehicles in the 1990 Clean Air Act amendments. Mr. Weaver was an expert witness for the U.S. Justice Department in its landmark “defeat device” case against the major heavy-duty diesel engine manufacturers. His work for the Gas Research Institute helped define the R&D program leading to today's ultra-clean natural gas engines.

As a consultant to the World Bank, Mr. Weaver played an important part in designing the Mexico City Transport Air Pollution Control Program, as well as similar programs in Bangkok, São Paulo, Santiago de Chile, Buenos Aires, and Colombo. He advised a committee that was appointed by the Indian Supreme Court to assess the court-ordered implementation of CNG buses and related control measures in Delhi. He contributed to the phase-out of leaded gasoline in Thailand, Mexico, Costa Rica, Chile, Peru, and Sri Lanka, and is the author of the “Implementer's Guide to Phasing out Lead in Gasoline,” distributed worldwide by the U.S. EPA and U.S. Agency for International Development.

Mr. Weaver received a Bachelor of Science degree in mechanical engineering from the University of California, Berkeley, in 1981 and a Master of Science degree in mechanical engineering from the Massachusetts Institute of Technology in 1985. He holds California Professional Mechanical Engineer's License No. M23320. 


EF&EE’s initial focus was on consulting regarding the measurement and control of air pollutant emissions from motor vehicles and other mobile sources. This included extensive work for the World Bank, UNDP, U.S. AID and other agencies, advising on emission-control strategies and air-quality programs in Mexico, Thailand, Egypt, and other developing countries. In the course of this work, EF&EE's staff literally “wrote the book” on strategies for controlling motor vehicle emissions in developing countries.

Our consulting work inside the United States focused on diesel emission-control technology and policies, and on alternative fuels. EF&EE carried out numerous studies of emission-control technologies and costs in support of various EPA rulemakings. A major study for the California Air Resources Board assessed the feasibility of emission control for locomotives, and proposed an innovative “bubble” approach to limiting railway emissions. 

In work for the Gas Research Institute and Natural Gas Vehicle Coalition, EF&EE staff helped map R&D programs leading to today's successful heavy-duty natural-gas engines and provided technical support for the development of appropriate emission standards and test procedures. The staff played an active role in the development of NGV codes and standards, both in the United States and internationally, and has advised on the feasibility, design, and implementation of NGV programs around the world. LPG, ethanol, and diesel emulsion fuels have been other areas of significant involvement.

EF&EE's research and development of on-board emission measurement systems began in 1994 and led to commercial sales of RAVEM™ systems beginning in 2003. We have also performed on-board and on-site emission measurements as a service since 2000. This has included programs to develop emission factors and/or evaluate emission-control technologies on ferryboats, diesel and gas-turbine locomotives, tractor-trailers, school buses, natural gas and diesel garbage trucks, diesel and gasoline hybrid vehicles, cranes, earthmoving machinery, and ships. 

Studies of selective catalytic reduction systems for the EPA and the American Petroleum Institute led EF&EE to become involved in the commercialization of SCR retrofit technology beginning in 2003. Sales of our Compact SCR™ systems for marine vessels began in 2007. Today, 11 Compact SCR™ systems are operating on diesel ferryboats in California. A Compact SCR™ demonstration project on a passenger locomotive was recently completed. 

EF&EE supplied its first Compact SCR™ system for a biogas engine in 2009. It was installed on a Guascor SFGLD 560 at Fiscalini Farms in Modesto—the first lean-burn biogas engine to meet California's “best available control technology” standard of 0.15 g/BHP-hr. The system is still in compliance after more than 24,000 operating hours on the original catalyst. Since, 5 more gaseous-fueled engines have been permitted with Compact SCR™ systems. Several more are in the construction process. The system has also been demonstrated on engines using propane and syngas from biomass gasification.