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YPSILANTI, MI – Auto makers can increase fuel economy further and faster by switching to diesel or hybrid-electric powertrains, but the exorbitant cost of such moves likely means gasoline engines will remain dominant in the U.S. for the next 15 years, a study by the National Academy of Sciences indicates.
The report, compiled by the NAS’s National Research Council with the help of industry experts, spells out the type of technologies already available for improving light-vehicle fuel economy and their associated costs. The study was commissioned by the National Highway Traffic Safety Admin. as it set new corporate average fuel economy targets for 2016, and much of its findings were cited in the agency’s final ruling released in April.
It took two years to compile the report, say its authors, who presented the survey- and research-based study publicly for the first time here at an event hosted by the Ann Arbor, MI-based Center for Automotive Research.
“Spark-ignition engines will still be the primary technology over the next 15 years,” says Trevor Jones, CEO of ElectroSonics Medical Inc. and longtime automotive electronics expert who chaired the research committee. “Diesel engines offer a substantial fuel-consumption reduction but at a high cost.”
It costs $74 for every 1% gain in efficiency eked out of a gasoline engine in a midsize or large car, Jones says, quoting the report. That compares with $137 for a switch to an HEV powertrain and $157 to move to diesel.
Unless there’s a spike in gasoline prices or diesel fuel prices become more favorable, consumers won’t want to pay for the added cost of compression-ignition technology, says Christopher Baillie, project manager for engineering specialist FEV Inc., who headed part of the study.
“The OEs have to sell these vehicles,” he says. “With spark-ignited technology, you can have smaller, incremental (fuel economy) improvements, while spending a few hundred (dollars) here, a few hundred there. There’s not that big (investment) jump in adding a diesel. Consumers are more willing to pay for that.”
Baillie says adding direct injection hikes gasoline engine costs a more reasonable $230-$480 per vehicle, while incorporating a turbocharger adds up to $1,000 per unit. Combined, those two technologies can boost fuel economy 8%-10%, he says.
