What is it?
As a result of BMW's engine downsizing programme, the 2.0-litre six cylinder turbodiesel in the 525d has been switched to a four for the 2012 model year 5 Series.
It is a change that has traded two cylinders for twin two-stage turbos and some handy gains in performance, economy and emissions reduction.
Power rises by 13bhp to 215bhp, while the 332lb ft torque peak streams in at 1500rpm to be sustained at that level for another 1000rpm. That's enough to score rapid 7.0sec sprints to 62mph, 149mph and 58.8mpg on the combined cycle - a 20 per cent reduction - and CO2 emissions that fall from 162g/km to 126g/km, an impressive result only diminished by the 119g/km achievement of the 520d EfficientDynamics.
Stop-start is now standard for the eight speed auto as well as the six-speed manual, while BMW's ambitiously named Driving Experience Control simultaneously alters the throttle response, ESP settings, power steering resistance and automatic transmission - shifts to produce Comfort, Sport, Sport+ and a fuel-saving mode called Eco Pro, which lowers the energy demands of the air conditioning and assorted electrical items.