A BMW i3 owner in the U.S. filed a lawsuit claiming that the electric vehicle can experience a sudden loss of power when a feature designed to nearly double its driving range is deployed.
The lawsuit, filed on Tuesday in Los Angeles federal court, seeks damages for i3 drivers nationwide and in California alone, or to force BMW to buy the vehicles back.
The suit singles out the range extender, an optional i3 feature in which a 34-horsepower, two-cylinder gasoline engine switches on when the vehicle's battery runs low, boosting the advertised range to 241km (150 miles) per charge from 130km (81 miles).
According to the plaintiff, Edo Tsoar, the i3's speed can plunge without warning if the vehicle is under a "significant load," including when it is filled with passengers or going uphill, when the range extender kicks in.
He said the loss of speed has happened to him "multiple" times, and that he now avoids driving farther than 80 miles.
The lawsuit also said drivers have told the National Highway Traffic Safety Administration that the speed of their i3 vehicles fell by half in similar incidents, even under full throttle.
"Having a sudden and unexpected loss of power in a motor vehicle can result in a catastrophic situation," Tsoar's lawyer, Jonathan Michaels, said in a statement on Wednesday. "These cars are dangerous and should not be driven."
BMW declined to comment.