Reducing emissions, improving fuel economy and drawing greater performance out of engines: requirements that are driving automotive manufacturers to seek out technology that will help them achieve these goals. One such technology on the rise is the variable valve timing (VVT) system, which influences the flow of gasses in and out of the combustion chamber through the opening and closing of the VVT valves to improve engine efficiency and fuel consumption. Many earlier systems worked only on valves and had no lift variation. Today, most modern systems can control timing and lift, and many automobiles rely on this core system, giving drivers a smoother, more even performance at higher RPM.