The breakthrough that will change hybrids and PHEVs, ZF presents its most revolutionary gearbox
A large number of plug-in hybrid cars feature six or seven-speed gearboxes, but not eight-speed ones like those found in gasoline or diesel vehicles. Manufacturers do not produce them because they are very expensive, but now ZF already has a transmission in its catalog, capable of handling more torque and power.
Only premium manufacturers, and not all of them, have eight-speed automatic gearboxes, brands that produce them in-house like Mercedes. A very expensive transmission to produce, especially when it is intended to be paired with high-voltage hybrid and plug-in engines. The components need to be more robust, which is why these transmissions with such a number of speeds are not common.
Typically, they are seven-speed, but a leading manufacturer like ZF has achieved what seemed impossible and has pushed the limits of MHEVs. Adding to its catalog an eight-speed automatic transmission for hybrids and PHEVs equipped with high-voltage batteries, which are the vast majority of the latest batch that already feature powerful 400 V batteries.
Powerful hybrids now have an 8-speed automatic transmission
The German company has reviewed all the components of a gearbox, with similar characteristics, that it had, so it has now developed new parts that better adapt to the high performance of electric motors, power electronics, and other mechanical components. The control unit has also been modified so that the transmission absorbs greater performance, but with less effort.
For example, in a configuration adapted to a plug-in hybrid (PHEV), the old ZF eight-speed automatic gearbox could only handle a maximum power of 218 hp and now that figure has been raised to an impressive 272 hp. The maximum electric motor torque has also increased from 500 Nm to 600 Nm, also highlighting a 28% reduction in losses at the input shaft, partly due to the use of fewer rare earths.
A transmission that increases range in hybrids
As a result, this new ZF gearbox allows for a 10% increase in range, compared to the previous model and with the same battery capacity. The specifications of this eight-speed automatic transmission are also designed for next-generation self-recharging hybrids, without external charging.
There are more and more 400 V hybrids that recharge while driving, either using the energy regeneration systems of the brakes, while also weighing less as they do not have large batteries. The transmission is not only lighter but also more economical. A further step in ZF's strategy, parallel to those of car manufacturers, in the increasingly growing world of hybrids, although this eight-speed automatic transmission is more focused on larger models, like SUVs, and manufactured in the United States.
