2014 BMW i3 REx range-extended electric car owned by Tom Moloughney - in dealership showroomEnlarge Photo
The BMW i3 is the only electric car in the world sold with an optional range-extending engine to increase driving capability beyond the range provided by the battery.
The "REx" option adds a small, 34-horsepower 650cc two-cylinder engine, derived from one used in BMW motorcycles, that powers a generator.
And as most owners of the BMW i3 REx model know—or learn while on the road—under a few circumstances, the small engine can't always provide enough electricity to the car to meet the highest demands.
That qualification is unique to the i3 REx, and now BMW is the target of a class-action lawsuit that alleges that the car can slow to speeds of 45 mph on highways, without warning, creating a safety hazard for drivers and passengers.
Indeed, many owners have experienced that behavior.
So have the three High Gear Media editors—Joel Feder, Bengt Halvorson, and John Voelcker—who've spent time with the BMW i3 REx under a variety of conditions.
2015 BMW i3 REx - Driven, Portland OR, April 2015Enlarge Photo
What happens is that the car simply loses power and slows from whatever speed it was maintaining to roughly 45 mph until the engine can recharge the battery enough to let it provide the necessary amount of current again.
In our experience, that occurs at high speeds, usually on long uphill stretches, perhaps with all four seats occupied, and more often in colder weather.
It's unexpected, and the first time it happens, it can be deeply disconcerting.
ALSO SEE: First Review In: 2014 BMW i3 Range Extender Performance Limited (Nov 2013)
It's a behavior described in one of the very earliest road tests of a BMW i3 REx, published in the U.K. in November 2013.
And in a way, it's surprising that it's taken two years since the car went on sale in the U.S. for liability lawyers to catch on.
The suit was filed by MLG Automotive Law, Newport Beach, California, on behalf of a claimant named Edo Tsoar.
2017 BMW i3Enlarge Photo
Green Car Reports reached out to BMW for a reaction to the lawsuit; spokesman Dave Buchko responded that BMW "cannot comment on pending litigation."
But the lawsuit wasn't a surprise to electric-car advocate Tom Moloughney, who bought the very first 2014 BMW i3 REx to be sold in the U.S. two years ago this month.
He said numerous i3 REx owners have contacted him, asking for help with the issue.
CHECK OUT: BMW i3 Electric Car: ReX Range Extender Not For Daily Use? (Mar 2013)
Moloughney said he was hit with a barrage of questions over the lawsuit yesterday when it was announced.
In response to a series of questions on the issue from Green Car Reports, Moloughney wrote:
The biggest problem is the lack of information on how the REx works at the dealership level. I think if people understood how the range-extender system works, then there would be fewer problems.
It wouldn't eliminate the issue, of course. If you continue to drive uphill at highway speeds for a prolonged time, the battery buffer will deplete and the REx won't be able to keep up with the energy demand.