This is what someone more clued up has to say on the subject:
Here’s a couple of bits and pieces about the mighty BMW 640d. Seems odd to be able to refer to a diesel as ‘mighty’ but such it is and a real sign of the times. I guess it shouldn’t come as too much of a surprise that diesels are finally where it’s at for real-world useable performance mated to stunning economy, given that diesel cars have dominated the winners enclosure at Le Mans for the past 5 or 6 years.
Anyway, for the record the 640d produces 313bhp and an eye-watering 465lbs/ft of torque, giving the Uber-coupe figures of 0-60mph in 5.3 seconds and onto an electronically governed top speed of 155mph. DMS and other such companies will further enhance the power levels to 380+ bhp and 580+lbs/ft torque for a modest sum (under £1k) and remove the top speed limiter at the same time, giving performance figures of circa 4.5 0-60 and 180+ mph. Add in sensational levels of in-gear acceleration to rival most supercars and a fantastic 8 speed gearbox that works brilliantly both as a flappy paddle manual AND as a full auto (very rare to have both work this well) and the ability to cross continents with ease, returning 50+ mpg and 850 mile range between fill-ups and I think you might begin to see why this middle-aged geezer is so interested in this level of middle-aged comfort :)