An initiative to reduce fuel combustions and emissions by the US Administration reopened a debate over tradeoffs between fuel economy and auto safety.

According to a survey by a group of organisations, fuel-economy standards force automakers to build more small cars, which leads to thousands of deaths in crashes annually.

The group, which aims to reduce problems related to fuel consumption and greenhouse-gas emissions includes the National Academy of Sciences, Insurance Institute for Highway Safety, Congressional Budget Office and National Highway Traffic Safety Administration.

The push toward smaller vehicles, which were often heavily discounted to sell, increases the death toll, the study says.

The Obama administration maintains that the new fuel standards can be met without forcing more small cars into the market.

White House Office of Energy and Climate Change director Carol Browner said that advanced technologies can be used to improve fuel efficiency without making major changes in their fleets.

According to environmentalists, lighter-weight materials and better designs can be used to meet higher fuel-economy or emissions standards.