If you know the current BMW 3 series and 4 series are cousins, you should have already known what has occurred on the 3 series will finally come to the 4 series, and this is exactly the case for the 2017 4 series.
All of these changes are related to BMW’s new engine family: the B47 (diesel, 4-cyl.), B48 (gasoline, 4-cyl.) and B58 (gasoline, 6-cyl.).
1. B58 Turbocharged I6 (440i)
The 2016 340i is the first application of the new B58 engine (we will have an detailed instrumented test review shortly, so stay tuned!), and followed by the 2016 740i (G11). Now it is 4 series’ turn: the 2017 440i will feature the same B58 I6 engine as the 340i, producing 320 hp and 332 lb-ft of torque.
The 2017 440i includes different trim and version combinations such as: RWD/xDrive, Convertible/Coupe/Gran Coupe.
We will have another detailed analysis of the B58 engine later after the 340i test drive review, however we have some preliminary discussion in one of our articles here:
Brief Analysis: the All-New BMW B58 6-Cylinder Engine
2. B48 Turbocharged I4 (420i, 430i)
Members inside the BMW’s B engine family have many designs/components in common. For example the blocks of the B58 and B48 share the same building structure, same bore and stroke etc. Their difference is just the former one has 2 more cylinders than the later one.
BMW provides two different tunes for the 4 series models which are using the B48 engine. The lower tune, making 180 hp and 200 lb-ft of torque, is named 420i; the higher tune is called the 430i, and it outputs 248 hp and 258 lb-ft.
The 2017 420i/430i includes different trim and version combinations such as: RWD/xDrive, Convertible/Coupe/Gran Coupe.
3. B47 Turbo-Diesel I4 (425d)
The B47 is the diesel version of the above B48 engine. In 425d’s application it is making 221 hp and 332 lb-ft of torque
At this moment, the 2017 425d can only be optioned as RWD, however, Convertible/Coupe/Gran Coupe versions are all offered.
We only have one official image for the 2017 4 series at this time (shown above), but we will keep you updated as more information is available.