The Economist A new type of engine for electric cars [...] But if Indigo Technologies of Cambridge, Massachusetts has its way, all this will change. Since the firm was founded in 2010 by Ian Hunter, a professor of mechanical engineering at the Massachusetts Institute of Technology, Indigo’s engineers have been developing an in-wheel drive system they call the T1. They believe that their system, a module that incorporates brakes, steering and an active suspension, as well as a motor, overcomes both the electrical problem and the unsprung-weight problem, thus paving the way for in-wheel drives to become mainstream. To reduce the electrical difficulties, the T1 runs at 48 volts instead of the 400 volts or more used by the motors in existing electric cars. The choice of 48 volts is not arbitrary. That voltage is also rapidly becoming standard for the circuits which run things like lighting, climate control, entertainment systems and adjustable seats, even in conventional combustion-engine-driven cars. Lowering the voltage almost tenfold in this way does, though, make the T1’s motor easier to protect and insulate, which in turn makes it cheaper to produce than higher-voltage motors, says Brian Hemond, Indigo’s boss. [...] Indigo is talking to carmakers and components firms and hopes, by the end of the year, to land its first production contract. Dr Hemond expects particular interest from firms developing ride-sharing and autonomous vehicles. The sort of small, sleek vehicles or personal-mobility pods which such in-wheel drive systems might inspire would be a world away from the perambulatory Lohner-Porsche. But they would have made Porsche himself wonder what might have been had he stuck with the electric motor.