Volkswagen chief executive Martin Winterkorn believes electric cars will struggle for years to achieve mass appeal.Winterkorn said: "Pure electric cars such as the e-Up! or e-Golf are likely to be bought as second cars, mainly because of their limited range and much higher purchase cost when compared to conventional vehicles with combustion engines." Winterkorn stressed the importance for VW's promotion of advanced hybrid technology and the potential of cars which mate an electric motor to a petrol or diesel engine.CONSUMERS DICTATE TECHNOLOGYHe said the Up car could be a candidate to use the ultra-frugal drivetrain used in the automaker's experimental XL 1 hybrid. The electric e-Up goes on sale later in 2013.Winterkorn said it's ultimately the consumer that determines the pace of technological innovation. The ambitious drops in C02 emission levels being sought in the European Union may only be achievable via state incentives to encourage people to buy such green cars, said the VW executive.