BMW Heaven - The Knowledge Base 2.0

  • Increase font size
  • Default font size
  • Decrease font size

6 Series Coupe and Cabrio Facelift - E63/E64 ( 2007 - ... ) - The 635d Straight-six Diesel

User Rating: / 115
Article Index
6 Series Coupe and Cabrio Facelift - E63/E64 ( 2007 - ... )
The early times for BMW Coupes
Design: Dynamics in Stylish Perfection
The 6 Series Convertible
Drivetrain: Superior Power, new Versatility
The 635d Straight-six Diesel
Effecient: Brake Energy Regeneration
Chassis, Suspension, Driver and Safety
Active Steering and Dynamic Drive
Active Cruise Control and Lane Departure Warning
Comfort and Safety
Features and Equipment
Navigation, Sound and BMW Individual
All Pages

A unique combination: straight-six diesel in the BMW 6 Series.
A truly unusual engine for two truly unusual cars: The enlargement of the engine range for the BMW 6 Series offers a unique combination, with diesel drive making its first appearance in this car segment. And indeed, this is a diesel which truly matches the character of both the Coupé and the Convertible, with BMW’s straight-six diesel featuring Variable Twin Turbo (VTT) technology bearing out the principle of EfficientDynamics at the highest level.
This is the world’s most powerful and sporting series engine of its kind, combining an outstanding dynamic driving potential with the right kind of economy for our current day and age. And given the smoothness and refinement typical of a BMW straight-six, this engine also offers a further forte greatly lauded and appreciated particularly in this segment of the market.
This unusual power unit clearly underlines BMW’s outstanding competence also in the development of the diesel engine, boasting technical features just as fascinating as the engine’s power and performance: With its all-aluminium crankcase, VTT turbocharger and the latest generation of common rail fuel injection, the engine develops maximum output of 210 kW/286 hp and peak torque of 580 Newton-metres/427 lb-ft.
Showing a DIN weight on the scale of 194 kg or 428 lb, this high-performance diesel is approximately 50 kg or 110 lb lighter than a comparably powerful eight-cylinder – ideal conditions, indeed, to give both the Coupé and the Convertible that supreme agility so typical of an outstanding BMW.


Optimised turbocharger technology, exemplary pulling force.
The six-cylinder diesel featured in the BMW 6 Series is an ongoing development of the power unit which, ever since making its debut in the BMW 535d, has been acknowledged worldwide as the benchmark for the modern, high-performance diesel. And indeed, the innovations now being introduced are not limited to the aluminium crankcase alone, since the further enhancement of efficiency offered by the new power unit is attributable above all to the optimisation of Variable Twin Turbo technology.
In the VTT charge process, the first step when the engine is still running at low speeds is the activation of a small turbocharger to provide additional boost from the ground up. Benefiting from its low level of inertia, this small turbocharger develops its boost effect spontaneously and without the slightest delay immediately when the driver barely touches the gas pedal.
Then, with engine speed increasing, the second, larger turbocharger also cuts in, ensuring that the engine reaches its maximum torque of 580 Newton-metres or 427 lb-ft at just 1,750 rpm. The interaction of the two turbochargers, finally, is masterminded by the particularly efficient, high-performance electronic engine management system.
Given this kind of power, the diesel versions of the BMW 6 Series clearly meet the great demands made particularly in this segment. Even more so, the unique pulling force and torque of this high-performance diesel adds another, very thrilling aspect to the dynamic character of the BMW 6 Series, with the BMW 635d Coupé accelerating to 100 km/h in 6.3 seconds, the BMW 635d Convertible in 6.6 seconds. Top speed, in turn, is limited electronically to 250 km/h or 155 mph.
Another truly impressive feature quite unprecedented in a car of this kind is the efficiency that comes with this performance: the BMW 635d Coupé makes do with a mere 6.9 litres/100 kilometres, the BMW 635d Convertible with 7.2 litres/100 kilometres in the EU test cycle, equal to 40.9 and, respectively, 39.2 mpg imp, meaning that both models set new standards in their segment also in this respect.
This very up-to-date economy most appropriate in this day and age has a significant influence on the grand touring comfort both cars are able to offer, with a substantial reduction in the number of refuelling stops on long distances. In practice, this means that the new BMW 635d Coupé has a range of up to 1,015 kilometres or 629 miles, the new BMW 635d Convertible up to 970 kilometres or 601 miles.


A further example of BMW’s competence in diesel engine technology is the exceptional smoothness and refinement quite unusual for a diesel, but quite normal for BMW in the 3.0-litre VTT power unit. Yet a further point is that the sound typical of a diesel engine has been further dampened and reduced on the BMW 635d Coupé and the BMW 635d Convertible by means of specific acoustic improvements.
Again, all this means that the “normal” driver will hardly even notice any difference between these models and their gasoline counterparts, neither will the driver experiencing these cars only occasionally, for example as a rental car.
Precisely this is why the BMW 635d Coupé and the new BMW 635d Convertible are equipped with a false tanking safeguard ensuring that the driver always uses the diesel pump at the filling station.
To optimise emission behaviour, BMW’s new high-performance diesel comes with a particulates filter of the latest generation as well as an oxidation catalyst both of which are housed in the same box. The exhaust treatment unit is positioned directly on the engine, thus reaching its operating temperature immediately after the engine has started and providing its full effect at a particularly early point in time. The particulates filter is maintenance-free and regenerates itself by burning the diesel particles. This ensures full function of the filter at all speeds and under all loads, without any influence on engine output and fuel consumption.

Last Updated on Monday, 12 April 2010 14:39  

Latest specifications

2008 Alpina D3 Biturbo LCI Sedan (E90)

2008 Alpina D3 Biturbo  LCI Sedan (E90)
View full specifications

2010 BMW 135i (E82)

2010 BMW 135i    (E82)
View full specifications

2011 BMW 640d A Coupe (F13)

2011 BMW 640d A  Coupe (F13)
View full specifications

2010 BMW 1 Series M Coupe (E88)

2010 BMW 1 Series M   Coupe (E88)
View full specifications

1994 BMW 740i A Sedan (E38)

1994 BMW 740i A  Sedan (E38)
View full specifications

Latest pictures