The Reagan Administration eased the Federal standard on automobile bumpers today, deciding to require that front and rear bumpers protect passenger cars from damage at impacts of 2 1/2 miles per hour or less. The current standard requires protection in crashes at 5 m.p.h. or less.
The National Highway Traffic Safety Administration said the new standard, which will take effect 45 days after publication in the Federal Register, would save consumers $300 million.
The agency also opened up the possibility of more lenient bumper standards in the future for some cars. Ralph Nader, the consumer advocate, called the move ''just outrageous.'' The decision ''will inflict almost half a billion dollars in added costs on motorists who are forced to buy automobles with creampuff bumpers,'' Mr. Nader said. ''The sales of replacement parts by the auto industry will go up and so will motorists' insurance premiums.''
Raymond Peck Jr., administrator of the traffic safety agency, said a regulatory analysis concluded that the new bumper standard would yield an additional $28 in net benefits to consumers over the life of the vehicle when compared to the current 5 m.p.h. standard.