The use of engine Variable Valve Technology (VVT) by North American vehicle manufacturers is set to rise sharply over the next five years according to a study by auto industry consultant and forecaster CSM Worldwide. The research concludes that the shift to VVT is being driven by pressure on manufacturers to have more Ultra Low Emission Vehicles (ULEV) in the production mix and increase Corporate Average Fuel Economy (CAFÉ) levels, while also offering a wide range of vehicle/powertrain packages.