Valvetronic (variable valves and electronics) is a valve drive system with fully-variable lift control of the intake valves (with lift varying from 0 - 9.7 mm).
Unlike all other petrol engines, it does not require a throttle butterfly, and engine output is controlled entirely by fully variable intake valves which regulate the amount of air (volume control) and reduce power loss considerably.
For BMW drivers, Valvetronic technology means lower fuel consumption and exhaust emissions, while at the same time improving performance and engine smoothness