The GM designed oil-cooled, permanent magnet motor is the heart of the Spark EV's propulsion system.

ENGADGET: Chevy Spark EV rated most efficient retail car with 82-mile range, 119 MPGe

The fall in the oil price, and the realisation that not much will be pumped from the new field until 2013, have cooled the fever.

ECONOMIST: Petrobras sets some ambitious targets