The intelligent energy management in the BMW X4 is provided by a number of standard-feature BMW EfficientDynamics technologies, including the Optimum Shift Indicator, the Auto Start-Stop function, Electric Power Steering and Brake Energy Regeneration.
The interplay between these technologies ensures the sustainable mobility of tomorrow − today.
Optimum Shift Indicator: Optimal, perfectly-timed gear changes can help save fuel, particularly in urban environments and over long distances. Optimal gear changes, less fuel consumption – the engine’s electronics system identifies the most efficient gear based on the driving situation and engine speed. An arrow lights up in the Info Display to show when it would be more efficient to shift into a higher or lower gear. The system also recognises when the car is accelerating quickly and will delay its recommendation accordingly until the engine speed has increased. Comparative tests have shown that vehicles with the Optimum Shift Indicator use around four percent less fuel.
The Auto Start-Stop function makes sure that fuel is only used when the car is actually driving. When the vehicle comes to a temporary standstill, for example at traffic lights or in stop-and-go traffic, the Auto Start-Stop function saves fuel by switching off the engine as soon as the car is idling and the foot is off the clutch (manual transmission), or when the care brakes to a complete standstill (Steptronic transmission).
A signal in the Info Display indicates that the Auto Stop-Start function is active. As soon as the clutch is pressed (manual transmission) or the foot taken from the brake (Steptronic transmission), the engine turns itself back on automatically.
The Auto Start-Stop function never compromises driving comfort and safety, as it remains inactive if the engine has not reached its ideal running temperature, the interior has not yet been sufficiently heated/cooled, if the battery level is too low or if the steering wheel is being turned. A central control unit restarts the engine if required, even when the car is at a standstill -- for example, if the car starts to roll forward or if the windscreen becomes foggy. The Auto Start-Stop function can be switched off at any time with the push of a button.
Electric Power Steering: Every time the driver steers, energy is consumed. But why should energy be consumed when the wheel is not being turned? BMW Electric Power Steering is only active when it is needed. Unlike conventional hydraulic steering systems, BMW EPS only uses energy when the wheel is actively being turned. When the steering wheel is static – e.g. when driving straight ahead along a motorway at high speed – the electric motor is inactive.
Brake Energy Regeneration: Every time the brakes are hit, kinetic energy is generated and until recently this energy went unused. Brake Energy Regeneration takes advantage of this long-overlooked potential. It harnesses the coasting energy that is generated whenever the driver brakes or takes his or her foot off the accelerator and turns it into electricity. This electricity is then used to charge the car battery. The intelligent energy management system means that the alternator no longer needs to run constantly, which reduces the strain on the generator. The result: reduced fuel consumption and increased performance – classic BMW EfficientDynamics.