The European automotive industry faces a major challenge to cost effectively control emissions while enhancing fuel economy. This paper examines the Euro 6 technical challenge for light duty diesel vehicles and describes technology which achieves emission compliance while lowering CO2. The paper firstly describes the progressive route being applied to lower NO(x) at source. The approach described as HPCC (Highly Pre-mixed Cool Combustion) avoids many of the pitfalls of very early injection or late injection strategies commonly reported. The approach selectively integrates advanced air and EGR (Exhaust Gas Recirculation) system developments, improved combustion system designs and control strategy. The paper explains that Euro 6 solutions are rapidly maturing and will restrict the need for NO(x) aftertreatment. Furthermore the HPCC strategy has been extended to achieve ultra low NO(x) combustion. In this regard, single cylinder research results have been successfully translated into demonstration vehicles. The paper shows 80-85% NO(x )reduction in combination with ~5% fuel consumption improvement is possible over the MVEG-B drive cycle relative to Euro 4 technology. In addition further reductions in fuel consumption are possible through the application of down-sizing and down-speeding strategies. The paper also describes a staged approach to lower CO2 in Diesel passenger cars. The authors suggest that a minimum change strategy which integrates engine, vehicle and low NO(x) technology will enable 25-30% CO2 reduction at Euro 6. Such technologies offer a cost effective alternative to intensive hybridisation strategies. The technology discussed will become a key component of global powertrain strategies. It can be used to enhance performance, lower CO2 or reduce the cost of emissions compliance depending on the application and market targeted.