The 48V mild hybrid offers a number of helpful system functions. In FMA (Freewheel, Motor Off) mode, the engine shuts off as soon as the driver takes his foot off the accelerator. The car then continues without consuming fuel. The engine is also hardly noticeable as soon as it is restarted. It is switched on and off without delay or loss of comfort, making the new Golf considerably more efficient.
To ensure that the driver does not feel any loss in driving comfort, the system has a socalled “Change-of-Mind-enabled” Comfort Start function. This means that if the driver presses the accelerator pedal again, the combustion engine starts immediately, with very few vibrations. This is another advantage of the BSG: in contrast to the sprocket starter, the driver experiences a quick and comfortable transition to the drive phase when starting. On 48V mild hybrid vehicles, however, the sprocket starter is only used for the first start. In contrast, the driver experiences a comfortable, fast and powerful transition when starting with the BSG - for example from sailing to a subsequent drive phase.
In order to use FMA operation as frequently and efficiently as possible, a predictive assistance function takes into account navigation data such as speed limits or bends in order to reach route points at the optimum speed and thus make the best possible use of the vehicle's kinetic energy.
Innovative technology with perspectives
For the year 2030, Volkswagen expects an electric share of its new vehicles of around 40 percent in Europe and China. The proportion of new vehicles with combustion engines will therefore continue to dominate for a long time to come. However, the efficiency of combustion engines is reaching its physical limits – which is where 48V technology will open new avenues up.
"You cannot afford to write the combustion engine off," said mobility expert Helmut List at the opening of the Vienna symposium last year. He warned against pursuing only one technology in order to meet future requirements. According to List, combustion engines, battery electric drives and fuel cells should have a synergy as combined building blocks.