Downsizing and Turbo Charging (TC) and Direct Injection (DI) may be combined with Variable Valve Actuation (VVA) to better deal with the challenges of fuel economy enhancement. VVA may control the load without throttle; control the valve directly and quickly; optimize combustion, produce large volumetric efficiency. Benefits lower fuel consumption, lower emissions and better performance and fun to drive. The paper presents an engine model of a 1.6 litre TDI VVA engine specifically designed to run pure ethanol, with computed engine maps for brake specific fuel consumption and efficiency. The paper also presents driving cycle results obtained with a vehicle model for a passenger car powered by this engine and a traditional naturally aspirated gasoline engine. Preliminary results of the VVA system coupled with downsizing, turbo charging and Direct Injection permits significant driving cycle fuel economies. be lower, but the use of a stoichiometric air-to-fuel mixture will permit better downsizing. Furthermore, the very well established three way catalytic converter technology may permit to meet emissions standards without the negative impacts on the after treatment technology that the lean stratified operation would introduce [16][17][18][19][20][21][22][23].The electro-hydraulic variable valve actuation technology may be applied to both intake and exhaust valves to fully modify the lift profiles as needed by the engine operation. In addition to valve timing strategies as early intake valve closure or late intake valve opening, valve lift strategies are also possible with variable valve actuation. Valve lift profiles may change not only in maximum lift and opening and closing times, but also in shape. Valve lift profiles may be different for the two intake valves of a typical four valve configuration to further control the swirl and tumble charge motions in the cylinder.In addition to metering the amount of air introduced within the cylinder and enhance the rate of combustion, variable valve actuation also offers the potential to improve other critical areas of spark ignition engines. These areas include better charging efficiency over the range of engine speeds and loads, improved dynamic response, better combustion evolution, improved operation during catalyst light-off time. Better details of the variable valve actuation system are proposed in a following section.The most part of gasoline engines now in production are naturally aspirated, port fuel injected, throttle controlled, stoichiometric engines with three ways catalytic after treatment with major advantage the low cost of production. The major downfalls of these engines are not only the low top brake efficiency, generally below 35%, but mainly the large penalties in efficiency reducing the load due to throttling, with efficiencies less than 15% during operation at 1 bar Brake Mean Effective Pressure (BMEP) and 1,500 rpm.