Report: Carmakers on Track for 54.5-mpg Mandate

The auto industry can achieve stringent 2025 U.S. corporate average fuel economy standards "on time, using known technologies and at reasonable cost," according to a pre-publication report from the National Research Council, a non-profit group that advises policymakers.

The 604-page study was sponsored by the National Highway Traffic Safety Administration, which oversees corporate average fuel economy standards. It will be used by carmakers, regulators and environmental groups in a midterm review of a plan to achieve an overall fleet average fuel economy for light vehicles of 54.5 mpg by 2025. The review will begin in 2016 and must be completed by April 2018.

One key finding: The NRC panel says a typical midsize car could use nothing more than a gasoline engine and such known technologies as turbocharging and lightweighting to meet the 2025 standard. Doing so would cost between $1,200 and $1,700 per vehicle, down from the $3,200 NRC estimated four years ago.

The study says carmakers will likely increase their use of such electrified alternatives as engine stop-start, hybrid powertrains and all-electric systems. But it says none of those options are necessary to meet the 2025 standard.

The report also points out that several top-selling, conventionally powered midsize cars already are ahead of earlier fuel economy milestones.

The 2025 goals will drive the continued development and improvement of powertrain designs, alternative fuels, advanced materials and architectural changes, the report says. But the authors expect most of the gains will come from improvements to gasoline internal combustion engines and other existing technologies and lightweight materials.

NRC says carmakers are likely to reduce vehicle weight more than it estimated previously. It now forecasts a 10%-20% reduction in the weight of passenger cars and a 15%-20% decrease for light trucks. The analysis anticipates no long-term safety implications in making vehicles lighter. But it concedes there could be higher interim risk until older and heavier vehicles are retired.

The authors say the continued transition to small turbocharged engines will yield fuel economy benefits but may cost more and produce less fuel savings than earlier estimates. They also call for additional research on vehicle size, fleet mixes and pricing to better understand the impact of the new rules on product offerings and consumer choices.

The NRC also urges NHTSA to:

• tap the onboard diagnostic (OBD) systems in cars to build a database to track real-life fuel efficiency of light-duty vehicles.
• drop its assumption that 50% of flex-fuel vehicles will use a fuel other than conventional gasoline.
• do a better job of assessing societal costs and benefits of its rules.
• explore the well-to-wheel effectiveness of raising the minimum octane level for gasoline, which would allow carmakers to improve the efficiency of their engines by raising the the compression ratio.
• add continuously variable transmissions to the technologies applicable to 2017-2015 CAFE standards.
• downwardly adjust its estimate of EV production when estimating manufacturing costs for electrics.
• find out why consumers tend to undervalue the economic benefit to them of owning a more energy-efficient vehicle.