BMW F13 640d Review by Carbuyer [Video]
The biggest diesel engine you could possibly get on a BMW these days is a 3-liter 6-cylinder one and you would definitely be pleased with it. The F13 640d is fitted with this engine that comes with 2 turbochargers and will send 313 HP to the rear wheels and get you to 100 km/h (62 mph) in 5.5 seconds.
It is a great car for cruising across a continent but, as everyone else already said, you really have to get the Adaptive Dampers option in order to feel really comfortable all the way.
Even though the engine has 2 turbochargers, the fuel consumption will not bleed you dry. Actually it has a combined efficiency of just 5.4 l/100 km (43 mpg) and that is most impressive for a car with 313 HP and 630 Nm (465 lb-ft) of torque.
Of course, you won't get too much room in the back but that's almost the only thing wrong with this car. Even the engine noise is impressive and doesn't sound like an oil-burner at all.
Overall, the 640d is a great car that offers you top performance for a fuel consumption that will make even 2-liter engines envious.