Diesel fuel was reformulated by reducing sulfur to < 0.005 wt-%, aromatics to < 20 vol-% and by limiting heavy polyaromatics. This reduced NOx, particulate, PAH and mutagenic emissions plus exhaust odor. Oxidation catalysts operated well.Less deposits formed in the EGR system. Fuel lubricity was enhanced by additives evaluated by injection pump tests and HFRR. Three years of field testing with 140 buses showed no fuel related problems. Oil change period could be lengthened and fuel consumption was unchanged.Demand for reformulated fuel was triggered by differentiating taxation based on quality. Fuels have been used since 1993 without problems. Life cycle analysis showed no increase of CO2.