A very recent conversation with people who would know of such things revealed that Fisker Automotive firmly intends to use a lighter weight dedicated three- or four-cylinder inline engine in the next generation of Fisker cars after the range of Karma variants and Delaware-built Project Nina models have all been launched.
So, rather than the 255-horsepower four-cylinder "LNF" 2.0-liter turbocharged GM Ecotec engine in the current Karma that weighs around 360 pounds, next-gen Fiskers will carry instead 200- to 250-pound turbocharged three-cylinder engines to create more than adequate energy to feed the lithium-ion battery pack.
One clear candidate drawing a lot of client attention is the Lotus Engineering 1.2-liter three-cylinder range-extending engine to be produced in Spain with Fagor Ederlan Group. The chief advantage to a dedicated extender engine is the lower weight versus a normal series four-cylinder pulled from the parts bin. This lightening will automatically add range to any electric vehicle.