From May, BMW will offer the X5 and X6 with an ‘Xdrive 40d’ powertrain with mild hybrid assistance. The 40d uses a 3.0-litre six-cylinder diesel engine with more power than the existing 30d model.
The new engine produces 340hp, with an additional 11hp contributed by a starter-generator. This means it slots above the xDrive30d with 265hp. In other markets, BMW also offers a 400hp M50d, but that is expected to be phased out.
The mild hybrid assistance also means that the X5 and X6 gain a ‘sailing function’. When coasting, the diesel engine can be turned off completely, because the 48V battery for the mild hybrid system can still supply power for the power steering and climate control.
BMW is currently at the front of the class when it comes to RDE2-compliant diesels and the X5 and X5 40d are no exception, although the hybrid 45e models, which combine a 3.0-litre petrol engine with a more powerful electric motor and larger battery, are likely to remain the more appealing option.
