The 730d has an engine based on the unit already in the 330d and 530d, although higher fuel injection pressure has resulted in improved power, up from 193bhp in the 5-series to 218bhp in the 730d. Torque has been improved and combined fuel economy is very similar to the 5-series, at 33.2mpg.
BMW claims the 730d will be the world's first diesel car to use a six-speed automatic gearbox. Top speed is 146mph and 0-62mph takes 8.0 seconds. No CO2 figure is available yet.
Prices have not been announced, although expect it to be very competitive against the S320 CDi, which means at least £48,000. The diesel S-class accounts for more than 50% of all S-class models sold in the UK.
BMW has also confirmed that it will produce a hydrogen-powered version of the 7-series.