Published June 07, 2010
New Federal standards for higher average gas-mileage in vehicles sold from now to 2015 will save consumers money on fuel. But the cars themselves are likely to cost more, according to a study released yesterday by the National Research Council.
Regular readers know we've been saying that it'll be a combination of smaller, more efficient engines, lighter weight, aerodynamics, and electronic smarts that'll let future cars go further on that precious (if underpriced) gallon of gasoline. Or, yes, maybe diesel.
At the request of the National Highway Traffic Safety Administration (NHTSA), the NRC panel took three years to assess the merits of different methods for improving gas mileage over a base 2007 vehicle. They confirm that combining various technologies will increase fuel efficiency without compromising either safety or performance.
Better gas engines: 29 percent
Updating standard gasoline engines with technologies like direct injection, turbocharging, and cylinder deactivation would reduce gasoline burned by 29 percent, at a cost to consumers of $2,200.
This is the approach taken by Ford, with its Ecoboost line of downsized, direct-injected, turbocharged engines offered in vehicles from the Lincoln MKT seven-seat crossover to the redesigned 2011 Ford Edge, plus a version of the upcoming 2012 Ford Explorer.
The 2011 Chevrolet Cruze Eco uses a small 1.4-liter turbocharged four to deliver the power previously offered by a 2.2-liter conventional gasoline engine. It costs $2,000 more than a base Cruze LS, which is fitted with a larger, less fuel efficient 1.8-liter four.
From gas to diesel: 37 percent
Replacing gasoline engines with diesel engines of equivalent power would cut fuel consumption by 37 percent, at an average added cost of approximately $5,900 per vehicle. Part of the cost is due to the more complex equipment needed to make them clean enough to meet more stringent U.S. emissions standards.
German makers Mercedes-Benz and Volkswagen have sold diesels in the States for years. More recently, they have been joined by Audi and BMW.
Hybrids: 43 percent
Adding hybrid powertrains instead would cut fuel consumption slightly more, a total of 43 percent, at a cost of $6,000. Here, obviously, Toyota is far and away the leader.
Acknowledging the reality that petroleum fuels will continue to power the vast majority of vehicles over the next decade and beyond, the panel said hydrogen fuel-cell vehicles "will not represent a significant fraction of light-duty vehicles on the road in the next 15 years."
EVs in "next decade" ??
As for the role of plug-in vehicles (from plug-in hybrids through pure battery electric cars), the report "predicted" that "small, limited-range battery electric vehicles" will be offered to car buyers "in the next decade".
Given that the 2011 Nissan Leaf will reach dealerships before the end of this year, that seems a fairly safe prediction. But the study did not assess the reduction in "wells-to-wheels" carbon output from driving on grid power, leaving that to other studies.
Payback not studied
The panel was specifically not charged with assessing payback periods for the various technologies; that task will fall to the regulatory agencies who will use the study, among other input, in writing the requirements.
It did, however, call for gas-mileage testing cycles to be updated from their present 1970s methods, to reflect real-world driving patterns and use of accessories in modern cars.
But don't just take our word for it. We encourage you to download a copy of the full report, entitled Assessment of Fuel Economy Technologies for Light-Duty Vehicles, and read it for yourself.