New York ground to a standstill last week when a camouflaged X3 like this one was mistaken for a car bomb because the tester left the engine running.

Slightly less dramatic, but no less important, this particular 2011 X3 - caught testing in the U.S. - could be BMW’s first mass-market electric hybrid. The alloy wheels it is fitted with are the same aerodynamic rims used on the X6 ‘ActiveHybrid’ model, designed to reduce wind resistance and increase fuel economy.

A hybrid 5-series appeared at the Geneva show earlier this year, but that was only a concept, and the X3 could be the first small BMW hybrid to make production.

Looks wise, changes to the X3 remain small, but the new model is slightly larger in dimensions than the one it replaces, with more prominent ‘kidney’ grilles and new wraparound headlights carefully disguised by the usual optical camouflage.

Joining this possible hybrid model will be a 2.0-litre diesel with 204bhp and expect to the appearance of the twin-turbo straight-six from the 335i as well.

The American-only hybrid X6 was powered by a 4.4-litre V8 mated to a pair of electric motors housed in the gearbox, but the technology could easily be altered to work with the smaller engines in the X3 line up.