BMW throws its evolved quad-turbo diesel engine into the 7 Series

Up until now, getting a diesel-powered BMW 7 Series meant you had to go for 730 or 740 model variants, but now BMW is adding a diesel powertrain to the 750 with the BMW 750d xDrive and BMW 750Ld xDrive. So not only do you have the choice between the normal and long-wheelbase 750, but you also get a brand new diesel engine that BMW claims to be the “world’s most powerful six-cylinder diesel engine.”

Back in July of last year, it was announced that BMW was considering a Quad-Turbo Diesel Engine, then just a few weeks ago, BMW unveiled its newest piece of engine evolution that sure did feature a total of four turbochargers. According to BMW, the new quad-turbo diesel engine offers a five-percent increase in horsepower and an 11-percent reduction in emissions output. We’ve known for a while that the engines first tour of service would be in the 750, but we didn’t know it would happen so quickly.

The 7 Series entered its sixth generation for the 2016 model year and was based on BMW’s modular CLAR platform – a platform that was focused on weight reduction and structural strength. As such, the car was redesigned from the ground up with a new Carbon Core passenger cell, a 50/50 weight distribution, and a whole new, sporty look. Here in the U.S. we only get gasoline-powered versions of the 740i and 750i, and sadly, the new 750d and 750Ld aren’t slated to cross the Atlantic either. Be that as it may, we decided to take a closer look at it anyway, so keep reading to learn more about the new 750Ld and 750d models.

Continue reading to learn more about the BMW 750d xDrive and BMW 750Ld xDrive.

  • 2017 BMW 750d xDrive and BMW 750Ld xDrive
  • Year:
    2017
  • Make:
  • Model:
  • Engine:
    inline-6
  • Horsepower @ RPM:
    400
  • Torque @ RPM:
    560
  • Displacement:
    3.0 L
  • 0-60 time:
    4.6 sec.
  • Top Speed:
    155 mph
  • car segment:
  • car fuel:
  • body style:
  • Overall:
    9/10

Exterior

When Bimmer “redesigned” the 7 Series, the exterior appearance didn’t really change much. The look of the 7 Series was essentially evolved to include BMW’s latest design language. Highlights of the new generation include the same kidney grille, a more aggressive front fascia wider and narrower headlights, sportier taillights, and integrated exhaust outlets in the rear. The only noticeable difference on the outside of the 750d models is the trim accenting along the side and across the front fascia is silver in color instead of chrome. Otherwise, the car shares the same appearance with the rest of its 7 Series stablemates, and as always the “Ld” model is just a bit longer than the standard 750d.

Interior

2016 BMW 7 Series Interior
- image 633429

On the inside, the 7 Series looks to be about as comfortable to ride in as you can get. The leather seats are soft and inviting, while the rear is designed for those who like to be driven. You’ll notice that the car comes standard with a panoramic roof but can be equipped with a Panoramic Sky Lounge LED Roof as an option. The technology inside is also better than ever. The new 7 Series sports the iDrive 5.0 infotainment system with a touch display and gesture control. The latter of which uses sensors to detect certain hand gestures to complete tasks like adjusting radio volume, accepting and rejecting telephone calls, operating the navigation system, and even turning off the screen. There is also a seven-inch, removable tablet that can be used by rear passengers to control the audio system and HVAC system.

Both the 750d and 750Ld will include all of these features along with that all-new quad-turbo diesel under the hood. As always the interior can be customized as much as you want with things like the Executive Lounge Seating Package, the Sky Lounge LED Roof, and a number of other options through BMW’s Individual division.

Drivetrain

2017 BMW 750d xDrive and BMW 750Ld xDrive High Resolution
- image 676330

This is where the 750d and 750Ld really stand out from the rest of the 7 Series lineup. That new quad-turbo diesel engine hiding under the hood of the two 750s is pretty amazing. That 3.0-liter, six-cylinder engine manages to deliver a total output of 400 horsepower and 560 pound-feet of torque, which is enough to take the 750d to 62 mph in 4.6 seconds and the 750Ld to the same benchmark in 4.7 seconds. Furthermore, it’s able to achieve a combined fuel economy of 5.7- to 5.9-liter per 100 km, or between 47.9 and 49.6 mpg on the imperial scale.

The 3.0-liter, six-cylinder engine manages to deliver a total output of 400 horsepower and 560 pound-feet of torque

This kind of fuel economy and performance is made possible by multi-stage turbocharging and an upgraded common-rail direct injection system. As always, the cylinder heads and engine block are manufactured using a high-pressure compression process, while a hot isostatic pressing process is used to ensure the aluminum castings can hold up to the extreme combustion pressures of the engine. The head gasket is now five layers think and the cylinder bores have a twin-wire, arc-sprayed coating. The pistons are made from aluminum and silicon alloy with remelted bowl rims and bronze lines inside the pin eyes. The fuel injection system has been upgraded to withstand fuel pressure higher than 2,500 bar – a way to increase the precision and automization of fuel, which essentially means less fuel is wasted.

The most important part is how the turbocharger system works. To make this next-gen engine, BMW had to add a fourth turbocharger to the mix. The high-pressure turbochargers are built into the same housing with variable turbine geometry. The larger, low-pressure turbocharger that was used in the past has been replaced by two smaller units that are able to respond faster. The result is almost zero turbo lag on takeoff and excessively quick response when the accelerator is mashed at higher speeds.

The way it works is, the two low-pressure turbos and one high-pressure turbo are in use at all times. Under hard acceleration from idle, the low-pressure turbos are bypassed. This allows turbo pressure to build up faster than ever, with the second high-pressure turbo kicking in at 2,500 rpm. Both low-pressure and high-pressure turbos now feature exhaust gas recirculation, which increases not only turbo performance but the performance of the engine itself. All told, this is the next evolution of the diesel engine, but Bimmer is keeping it on that side of the world for now, so don’t expect to see it in the U.S. anytime soon.

Prices

BMW has yet to release pricing for the 750d xDrive or the 750Ld xDrive. The 750i xDrive and 750Li xDrive start out at €109,900 and €115,100, respectively. With that said, you can expect a similar price point when the 750d xDrive and 750Ld xDrive go on sale in July of this year. That translates to $123,964 and $129,884 at current exchange rates.

Competition

Mercedes S-Class

2014 Mercedes-Benz S-Class High Resolution Exterior
- image 506431

Mercedes keeps its diesel-powered S-Class out of American hands just like Bimmer does with its diesel-powered variants of the 7 Series. For competition against the 750d or 750Ld, you’ll need to look to the Mercedes S350 BlueTec. It is powered by a 3.0-liter diesel engine that delivers 258 horsepower and 457 pound-feet of torque. That’s a deficit of 142 horsepower and 103 pound-feet in comparison to the 7 Series, but this generation of the S-Class is also a couple of years old now. On top of that, the deficit in power comes at a cheaper price as well. At the time of this writing, the standard length 350 BlueTec starts out at €82,229, while the long-wheelbase model starts out at €87,762. That converts to $92,689 and $98,926 at current conversion rates.

Read our full review on the Mercedes S-Class here.

Conclusion

2017 BMW 750d xDrive and BMW 750Ld xDrive High Resolution Exterior
- image 676329

It was only a matter of time before Mercedes jumped up to using four turbos on its diesel engines, but I’m impressed to see that the manufacturer took the time to do it right. Instead of just throwing a fourth turbo in the mix, Merc redesigned the entire turbo system with the two high-pressure turbochargers built into the same housing and two low-pressure turbochargers instead of a single large unit. On top of that, Mercedes upgraded the injection system and strengthened the head gaskets as well. In the end, it developed a stronger, more powerful, and more efficient diesel powertrain. It’s no surprise the Mercedes is debuting this upgraded diesel engine in the 750, but with any luck, it will trickle down the lineup in coming years.

  • Leave it
    • Not coming to the U.S.

Press Release

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).

2017 BMW 750d xDrive and BMW 750Ld xDrive High Resolution Exterior Wallpaper quality
- image 676328

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.

2017 BMW 750d xDrive and BMW 750Ld xDrive High Resolution Exterior
- image 676329

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.

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