The Suzuki Samurai is so unstable it "literally trips over its own feet" and rolls over, says the publisher of Consumer Reports, which gave the popular sport vehicle its first "not acceptable" rating in 10 years.

But the American Suzuki Motor Corp. defended the Japanese-built Samurai as safe and said there was no justification for the magazine publisher's claim that it should be banned because it tends to turn over in sudden turns.Consumers Union, publisher of Consumer Reports, said Thursday the Samurai is too short, too narrow, too light and has too high a center of gravity to be safe. It asked federal regulators to recall the more than 150,000 Samurais sold in this country and provide refunds to owners.

Consumers Union called the four-wheel-drive sport utility vehicle "wholly unsuitable for consumer use" in a petition filed with the National Highway Traffic Safety Administration.

"That car literally trips over its own feet, and I wouldn't want to be in it," said R. David Pittle, technical director of Consumers Union, at a news conference. "They're promoted as safe, fun vehicles, when the fact of the matter is, they're not."

Consumers Union said the $8,500 Samurai was the first car out of 349 tested in the last decade to roll over during a routine accident-avoidance test, in which cars are made to swerve to avoid an obstacle in the road.

Consumers Union officials showed a videotape in which the Samurai lurched onto two wheels and began to roll over when it suddenly changed lanes at just under 40 mph. Arm-like extensions installed to protect the test drivers prevented the car from rolling onto its side.

The Samurai's major competitors, the Jeep Wrangler, the Jeep Cherokee and the Isuzu Trooper, were shown making the same maneuver without losing stability at speeds higher than 40 mph.