BMW Blog published an interesting editorial about what they saw on the BMW X3 and what it tells about the F30 3 Series. The article magnifies the little important things that BMW does in order to reduce carbon emissions and increase fuel efficiency, and how BMW needs to not sacrifice the driving dynamics of the F30 3 Series despite all these. Here is an excerpt of the editorial:

Electronic Power Steering (EPS)

The ZF 8HP transmission is another piece of EfficientDynamics. It’s about six percent more efficient than the 6 speed auto it replaces but it has some additional tricks above and beyond enhanced fuel economy.

The core of the transmission is four epicyclic gear sets and five shifting elements. That gives it eight forward speeds and reverse. In a conversation with a BMW engineer, I facetiously asked how many reverse gear ratios they could do, he chuckled and said a few but didn’t think they would ever introduce a car with more than one.

The truly trick piece of this tranny is that it can accept a variety of interfaces between the engine and tranny core. There’s the usual torque converter, that’s ubiquitous in automatic transmissions (the torque converter obviates the need for a clutch between the engine and tranny). It can also be equipped with an electric motor. Soon more BMWs will
utilize the electric motor nose that will hybridize the car. We’ve published rumors of a diesel four cylinder X5 utilizing the electric motor nose of the 8HP. Expect a four cylinder F30 with that nose in the near future. Then there is also a dual-clutch module that could possibly replace the existing DCT.

An additional feature, from a fuel economy standpoint, is that the ZF 8HP is the first automatic that is compatible with stop/start. We sampled stop/start in the press preview of the X3 and came to the conclusion that it will feel totally seamless when coupled to the hybrid (electric motor) module.



Eight Speed Automatic

The ZF 8HP transmission is another piece of EfficientDynamics. It’s about six percent more efficient than the 6 speed auto it replaces but it has some additional tricks above and beyond enhanced fuel economy.

The core of the transmission is four epicyclic gear sets and five shifting elements. That gives it eight forward speeds and reverse. In a conversation with a BMW engineer, I facetiously asked how many reverse gear ratios they could do, he chuckled and said a few but didn’t think they would ever introduce a car with more than one.

The truly trick piece of this tranny is that it can accept a variety of interfaces between the engine and tranny core. There’s the usual torque converter, that’s ubiquitous in automatic transmissions (the torque converter obviates the need for a clutch between the engine and tranny). It can also be equipped with an electric motor. Soon more BMWs will
utilize the electric motor nose that will hybridize the car. We’ve published rumors of a diesel four cylinder X5 utilizing the electric motor nose of the 8HP. Expect a four cylinder F30 with that nose in the near future. Then there is also a dual-clutch module that could possibly replace the existing DCT.

An additional feature, from a fuel economy standpoint, is that the ZF 8HP is the first automatic that is compatible with stop/start. We sampled stop/start in the press preview of the X3 and came to the conclusion that it will feel totally seamless when coupled to the hybrid (electric motor) module.



FlexRay

This is a little known piece of gear that allows a great deal more integration of the various vehicle electronic modules. It is migrating down from the 7 and 5ers into the F30. It will find its way into pretty much the entire model range before long. The cost of development requires that it be spread across as many units as possible.

FlexRay acts as a ‘bus of buses’, it basically is a high bandwidth bus that interfaces to the lower bandwidth CAN buses utilized by the majority of the vehicles electronic modules. It doesn’t just act as an interconnect though. It also routes priority messages between buses. One way of grasping what FlexRay allows is to think about the communication
required between the cruise control code, ECU, and the ABS system in an active cruise control, stop and go, system.

Source: BMW Blog