Engine options for the car of tomorrow: Competing internal and external combustion engines, as well as electrics, are considered as contenders

Predicting what engine will power tomorrow's cars goes far beyond the technical feasibility of meeting emissions and fuel-economy requirements. Such forecasting encompasses the traditional pressures of competition, cost, and consumer acceptance — as well as performance, durability, and serviceability, along with requirements for training and parts supply. Uncertainty as to the type of fuel available is another complicating factor. R&D costs and the availability of capital for tools and facilities are also considerations.