MIT Scientists Say U.S. Can Halve Gas Consumption Using Hybrid Autos

How much gasoline could US citizens save by driving around in light-weight hybrid vehicles? Up to half what they currently use, say scientists at MIT.

The US consumes about 140 billion gallons of gasoline each year. A team of researchers led by MIT professor John Heywood has completed a five-year assessment that shows that we can halve gas consumption.

How much gasoline would the nation save in the year 2035 if lightweight hybrid and plug-in hybrid vehicles dominated the marketplace? The MIT team says more than 68 billion gallons, or about half the fuel currently used by today's vehicles.

The report concludes that over the next 25 years the fuel consumption of new vehicles could be reduced by 30-50 percent and total U.S. fuel use for vehicles could be cut to 2000 levels, with greenhouse gas (GHG) emissions cut by almost as much.

"We've got to get out of the habit of thinking that we only need to focus on improving the technology—that we can invent our way out of this situation," said John B. Heywood, the Sun Jae Professor of Mechanical Engineering, who led the research. "We've got to do everything we can think of, including reducing the size of the task by real conservation."

The researchers stressed that carefully crafted government policies will be needed to bring about this large-scale move away from business as usual.

The new report, On the Road in 2035: Reducing Transportation's Petroleum Consumption and GHG Emissions, integrates five years' work by MIT teams examining different approaches to cutting transportation fuel use and emissions. Projects analyzed specific propulsion technologies, vehicle performance and design, market penetration rates for the various technologies, consumer expectations, new fuels, and potential policy measures.

Slashing transportation fuel use and GHG emissions by 2035 will require immediate action on several challenging fronts. The following steps are key.

For the near term (up to 15 years), we should increase our efforts to improve light-duty vehicle engines and transmissions, but all improvements must go towards reducing fuel efficiency rather than making cars bigger and faster. Also critical is reducing vehicle weight and size.

For the mid and long term (15-30 years, and more than 30 years), we should ramp up work on radically different technologies such as plug-in hybrids and hydrogen fuel cell vehicles.

We must also develop and market more environmentally benign fuels based on non-petroleum sources. For example, research on biofuels should continue. The US emphasis on corn-based ethanol is not obviously justifiable, but biofuels based on other feedstocks and conversion technologies should be pursued. In general, the use of biofuels will grow but not as fast as expected just a few years ago.

The final key is policy action. A coordinated set of regulatory and fiscal measures will be needed to push and pull improved technologies and greener alternative fuels into the market place in high volume. Measures should require auto manufacturers to make smaller, more-efficient cars, encourage consumers to choose those vehicles, and discourage everyone from driving so much.

Overall, the report shows that there are many opportunities for change. However, the challenges involved are enormous.

Despite the hurdles, he and his team estimate that by improving fuel efficiency over the next 15 years and bringing in "radically different" cars including hybrids and possibly fuel cell cars in the next 30, it should be possible to slash the amount of fuel guzzled by the gas-guzzling nation by 30% to 50% by 2035.

"Transitioning from our current situation onto a path with declining fuel consumption and emissions, even in the developed world, will take several decades—much longer than we had hoped or realized," said Heywood. "We've got to start now."

Posted by Jason McManus.