Celebrating its premiere in the BMW 7 Series model range: the world’s most powerful six-cylinder diesel engine.

Munich. An impressive spread of innovations mark the
new BMW 7 Series luxury sedan out from the crowd. The spread of new
features runs from a Carbon Core body structure and BMW eDrive
technology in the three BMW iPerformance models to BMW gesture control
and Remote Control Parking. And now another new arrival has joined the
fray. The world’s most powerful six-cylinder diesel engine is making
its debut in the BMW 750d xDrive and BMW 750Ld xDrive (fuel
consumption combined: 5.9 – 5.7 l/100 km [47.9 – 49.6 mpg imp]; CO2
emissions combined: 154 – 149 g/km), which come as standard with
intelligent all-wheel drive. The new unit generates maximum output of
294 kW/400 hp and peak torque of 760 Newton metres (560 lb-ft).

The new 3.0-litre six-cylinder in-line engine was developed on the
basis of the BMW Group’s latest generation of power units. Its BMW
TwinPower Turbo technology includes multi-stage turbocharging with
four turbochargers and common-rail direct injection, the latest update
of which generates maximum pressure in excess of 2,500 bar. These and
other technological highlights allow significant improvements to the
already exceptional power delivery, pulling power and efficiency
achieved by the outgoing engine. The new BMW 750d xDrive accelerates
from 0 to 100 km/h / 62 mph in 4.6 seconds (BMW 750Ld xDrive:
4.7 seconds) – an improvement of 0.3 seconds over its predecessor.
Much credit for this even sharper dynamic edge can go to a new form of
multi-stage turbocharging, which now brings together four
turbochargers in place of the previous three. This enables boost
pressure to be built up even more quickly at lower engine speeds and
therefore prompts incredibly swift responses to throttle applications
from idle.

 

Top-level efficiency: engine output up 5 per cent, average
fuel consumption down 11 per cent.

The new generation of the world’s most sportingly gifted six-cylinder
diesel engine develops its maximum output of 294 kW/400 hp at
4,400 rpm. Its optimised performance characteristics are reflected
most prominently in torque development that gathers pace rapidly and
from low engine speeds. Indeed, the engine serves up over 450 Newton
metres (332 lb-ft) of torque at just 1,000 rpm and puts its maximum
760 Newton metres (560 lb-ft) on tap between 2,000 and 3,000 rpm. The
engine’s large and sustained wave of thrust and the eight-speed
Steptronic transmission tuned to make the most of it together ensure
that instant and ferocious bursts of pace can also be achieved under
throttle inputs at higher speeds. The BMW 750d xDrive and BMW
750Ld xDrive have an electronically limited top speed of 250 km/h (155 mph).

Added to which, the most powerful diesel engine ever offered by BMW
also stands apart with a balance of brawn and fuel economy unmatched
by any rival in this engine segment. A 14 kW/19 hp (i.e. 5 per cent)
increase in output and peak torque up by 20 Newton metres (15 lb-ft)
are accompanied by a 11 per cent reduction in average fuel consumption
and emissions over the predecessor model. The new BMW 750d xDrive and
new BMW 750Ld xDrive record combined fuel consumption of between 5.9
and 5.7 litres per 100 kilometres (47.9 – 49.6 mpg imp), while CO2
emissions are 154–149 grams per kilometre (figures based on the EU
test cycle, may vary depending on the tyre format specified).

 

Performing at its best under high pressure: new
top-of-the-line diesel features numerous technological highlights –
from cylinder head to exhaust treatment.

The new sporting king in the diesel ranks represents a masterful
example of the engineering art and further evidence of the BMW Group’s
outstanding expertise in drive system development. A host of
innovative features in the engine’s construction have enabled the
signature benefits of diesel engines in terms of power delivery and
efficiency – underpinned by the principle of combustion under
extremely high pressure – to be showcased at the highest level.
Essential foundations had already been put in place in the development
of the base engine, a member of the BMW Group’s latest generation of
drive systems. Specific detail solutions address both the thermal and
mechanical loads that come with extremely high outputs and the
increase in maximum combustion pressure – from the previous engine’s
200 bar to 210 bar.

As with the outgoing unit, the cylinder head and crankcase are
manufactured in a special high-pressure compression process. Hot
isostatic pressing (HIP) ensure the aluminium castings are
particularly strong. The assembly of the main bearing caps and
cylinder head is based on a tie rod concept, complete with a central
screw to give extra strength. Other special features include the now
five-layer cylinder head gasket, cylinder bores with a twin-wire
arc-sprayed coating and pistons made from an aluminium/silicon alloy
with remelted bowl rims, bronze liners in the pin eyes and centrally
controlled cooling.

The latest generation of common-rail direct injection technology
takes care of the fuel supply. The piezo injectors, whose maximum
injection pressure has been increased to over 2,500 bar, ensure
extremely precise metering and fine atomisation of the fuel. As a
result, the engine’s efficiency has increased and its emissions have
been reduced. The exhaust treatment technology at work in the BMW
750d xDrive and BMW 750Ld xDrive includes not only a diesel
particulate filter and NOX storage catalytic converter, which are
positioned in a combined housing close to the engine, but also an SCR
(Selective Catalytic Reduction) system with AdBlue injection.

 

Treading new ground: four turbochargers working together as a
precisely coordinated team to deliver enhanced driving pleasure.

The effectiveness and performance characteristics of the new engine
are determined largely by the first ever use of a fourth turbocharger
and, above all, the precisely coordinated interplay of all the
components in the turbocharging system. As with the outgoing engine,
the performance-boosting flow of compressed air into the combustion
chambers is generated by multi-stage turbocharging. The high-pressure
stage revolves around two compact turbos with variable turbine
geometry integrated into a single housing, while a single, very large
low-pressure turbocharger has been replaced by two smaller – and
therefore faster-responding – units. The latest-generation Digital
Diesel Electronics (DDE) responsible for engine management adopt a
precisely defined deployment strategy to coordinate the activity of
the individual turbos, the position of the high-pressure system’s
variable vanes, and the regulation of the change-over and bypass
flaps, the exhaust gas butterfly valve, the wastegate and the
intercooler in response to the operating situation and throttle inputs.

Generally speaking, the two low-pressure turbochargers and one of the
two high-pressure turbos are permanently in action. Only under hard
acceleration from idle will the two low-pressure turbochargers be
bypassed by means of a flap control system. This allows boost pressure
to be built up even more quickly. The second high-pressure
turbocharger is brought into play at an engine speed of about 2,500 rpm.

Another new feature not present in the outgoing engine is exhaust gas
recirculation for the low-pressure stage of the turbocharging system
as well as the high-pressure stage. This measure increases the
effectiveness of the turbochargers and therefore of the engine as a
whole. In this way, levels of nitrogen oxide emissions under high
loads are also reduced. To enhance efficiency, the engine also employs
an indirect system of charge air cooling with higher capacity than
that used by the outgoing engine, as well as additional compressor
backplate cooling for the low-pressure turbochargers. Key to the
latter is a separate low-temperature circuit – independent of the
engine’s cooling system – which includes heat exchangers and an
electrically operated coolant pump.

The BMW 750d xDrive and BMW 750Ld xDrive will be available from July 2016.

 

 

 

 

 

 

 

 

Manual on fuel consumption and CO2emissions:

For further details on official fuel consumption figures,
official specific CO2emissions and power consumption of new cars,
please refer to the “Manual on fuel consumption, CO2 emissions
and power consumption of new cars”, available at sales outlets,
from Deutsche Automobil Treuhand GmbH (DAT), Hellmuth-Hirth-Str. 1,
73760 Ostfildern-Scharnhausen and at
http://www.dat.de/angebote/verlagsprodukte/leitfaden-kraftstoffverbrauch.html.
ManualCO2 (PDF – 2.7 MB)