 The electronic control of direct injection really made a difference in terms of emissions, refinement and power.All earlier generation car direct injection diesel engines benefit greatly from the use of biodiesel fuel, which reduces emissions and greatly improves refinement without engine modifications, provided they use compatible 'Viton' type rubber in their fuel systems.The diesel car markets are the same ones who pioneered various developments (Mercedes-Benz, BMW, Peugeot/Citroën, Fiat, Alfa Romeo, Volkswagen Group) There were also small diesel engines produced in England by British Leyland and Perkins.