Well, that's apparently what a new report for MIT is saying!
Check it out (summary from Andrew Williams at Gas2.org):
A new report by the Massachusetts Institute of Technology (MIT) Energy Initiative predicts that a 30-50% reduction in fuel consumption is possible in the US over the next 25-30 years. Initially, this will be achieved through improved gasoline and diesel engines and transmissions, gasoline hybrids and reductions in vehicle weight and drag. In the longer term, the study concludes that plug-in hybrids and, later, hydrogen fuel cells may begin to have a significant impact on fuel use and emissions.
The report, ‘On the Road in 2035: Reducing Transportation’s Petroleum Consumption and GHG Emissions,’ summarizes the results of an MIT research project that assessed the technology of vehicles and fuels that could be developed and commercialized during the next 25 years.
The research team assessed the effect of new vehicle and fuel technologies on the performance, cost and lifecycle emissions of individual vehicles. It then assessed the effects on the total on-the-road fleet of introducing these technologies using “plausible assumptions about how rapidly they could be developed, manufactured and sold to buyers to replace existing vehicles and fuels or to add to the existing fleet.”
Other key findings include:
- Alternative fuels simpy seeking to replace petroleum are unlikely to lead to a significant change in GHG emissions. In fact, major near-term alternatives like the Candian oil-sands and coal will actually increase emissions;
- Although some biofuels may prove beneficial, the U.S. emphasis on corn-based ethanol is “not obviously justifiable,” since it has “high economic costs, questionable GHG advantages, and other unfavorable environmental impacts.”
- No single alternative fuel or technological development is likely to solve the problems of increased GHG emissions. Instead, progress must come from from a “comprehensive, coordinated effort to develop and market more efficient vehicles and benign fuels, and to find more sustainable ways to satisfy transportation demands.”