Most of the infant car seats tested by Consumer Reports "failed disastrously" in crashes at speeds as low as 35 mph, the magazine reported Thursday.

The seats came off their bases or twisted in place, the report said. In one case, a test dummy was hurled 30 feet.

Of the 12 car seats tested, Consumer Reports said it could recommend only two, and it urged a federal recall of the poorest performing seat, the Evenflo Discovery.

Consumer Reports magazine backed off Thursday from its recent negative report on infant car seats, saying test crashes were conducted at speeds higher than it had claimed.

The magazine reported earlier this month that most of the seats it tested "failed disastrously" in crashes at speeds as low as 35 mph.

In one test, it said, a dummy child was hurled 30 feet.

In a statement issued, Consumer Reports said it had received information from the National Highway Traffic Safety Administration about the speed at which the side-impact tests were conducted -- supposedly, 38 mph.

The National Highway Traffic Safety Administration said the crash tests were conducted under conditions that would represent being struck at more than 70 mph -- twice as fast as the magazine claimed.