Key among the modifications brought to the popular executive class saloon and estate is a new-generation turbocharged 2.0-litre four-cylinder diesel engine that is claimed to provide improvements to performance, fuel economy and CO2 emissions.
The B47 designated unit, first unveiled in the facelifted BMW X3, uses the latest common rail injector technology, endowing the reworked 518d with 148bhp and 295lb ft of torque – an increase of 7bhp and 15lb ft on the existing model.
The 520d’s reserves have been boosted by 6bhp to 187bhp, with torque increasing by a similar 15lb ft to the same 295lb ft as the 518d.
Allied to the new engine is a reworked version of BMW’s eight-speed automatic gearbox, which is claimed to bring further fuel savings.
A six-speed manual remains standard on both models. BMW’s official performance claims give the 518d and 520d saloon respective 0-62mph times of 9.5sec and 7.9sec in combination with the optional automatic gearbox, with the 518d and 520d Touring put at 9.9sec and 8.1sec.
At a claimed 65.7mpg and 114g/km, the 518d saloon improves on today’s model by 3.0mpg and 5g/km in automatic guise, with the new 518d Touring recording a combined cycle figure of 61.4mpg.
The 520d saloon is claimed to offer even greater fuel savings. Its 68.9mpg and 109g/km betters today’s model by 6.2mpg and 10g/km when running the revised automatic gearbox. Meanwhile, the 520d Touring is rated at the same 61.4mpg as the 518d Touring.