BMW unveils new 7 Series; battery-electric i7
21 April 2022
BMW unveiled the seventh generation of its 7 Series, including the first all-electric i7 XDrive60. (Earlier post.) Three models are available at launch, including the i7 EV.
The 2023 BMW 740i is powered by a thoroughly upgraded version of the iconic B58 3-liter TwinPower Turbo inline six-cylinder engine. Now dubbed B58TU2, the new Miller cycle six-cylinder features redesigned intake ports and combustion chambers, electronically controlled VANOS variable camshaft timing, and 48-volt mild hybrid technology.
The 760i xDrive combines the power of the 4.4-liter TwinPower Turbo V8 with BMW xDrive intelligent all-wheel drive. The new V8 borrows technology from BMW Motorsport, and features a new exhaust manifold, external oil cooling, and further developed turbocharging. The V8, too, gains 48V mild hybrid technology, and with the electric motor integrated into the new eight-speed Steptronic Sport transmission delivers the twin benefits of optimized response and power delivery under acceleration, and greater efficiency thanks to adaptive recuperation.
Featuring two highly efficient current-excited electric motors with a combined output of 536 horsepower and 549 lb-ft of instantaneous torque, the i7 xDrive60 will sprint from 0-60 in about 4.5 seconds while returning an estimated range of up to 300 miles (estimated range of up to 300 miles according to preliminary BMW AG tests based on the EPA’s test procedure standards).
The electric motors work according to the principle of an electrically excited synchronous motor, where it is a precisely controllable electrical feed that sets the rotor in motion rather than fixed permanent magnets. This design precludes the need for rare earth metals altogether in the manufacture of the rotor.
The virtually silent power delivery of the BMW i7 xDrive60 is further helped by improvements to the electric drive units’ acoustics, a model-specific mounting concept and newly developed noise encapsulation for the electric motors. The motor driving the rear wheels generates peak output of 308 bhp, while the unit at the front axle produces 255 bhp. The top speed of the new BMW i7 xDrive60 is electronically limited to 149 mph.
The new BMW 7 Series - Gen5 BEV Technology
Underpinning the dynamic prowess of the BMW i7 xDrive60 are its electric all-wheel drive and its precisely tuned driving stability systems headlined by the near-actuator wheel slip limitation. The fully variable drive system is intelligently connected with the system of powertrain and chassis control functions, whose extremely quick and precise responses help to sustain forward momentum even in adverse road and weather conditions.
The extremely slim high-voltage battery with a cell height of just 4.3-inches is located low down in the vehicle floor and provides 101.7 kWh of usable energy. The heat pump technology used in the integrated heating and cooling system for the cabin and drive system also helps boost efficiency, as does the adaptive or individually adjustable recuperation feature. The high-voltage battery is heated using a dedicated 5.5 kW electric flow heater.
The adaptive recuperation feature familiar from the BMW iX and BMW i4 models has been further honed for the BMW i7 and is now also able to take downhill sections and information from the traffic light recognition function into account.
Adaptive recuperation generally allows the intensity of brake energy regeneration during deceleration and braking to be optimized automatically for the road situation, as detected using data from the navigation system and the driver assistance systems’ sensors. When approaching an intersection, for example, the level of recuperation can be increased—even if route guidance isn’t activated—thereby feeding energy back into the high-voltage battery while harnessing the deceleration effect at the same time.
On the open road, meanwhile, the coasting function can take over, allowing the car to “freewheel” with no drive power whenever the driver eases off the accelerator. Energy is no longer supplied to the two electric motors in this state, meaning no battery power is consumed.
Adaptive recuperation is the default setting in driving position D. Alternatively, the driver can choose a high, medium, or low brake energy regeneration setting for all driving situations in the BMW iDrive menu. The highest recuperation setting is automatically activated in driving position B, which also produces the characteristic one-pedal feeling.
Information on the energy flow can be viewed in the control display no matter which driving position is selected. The range horizon clearly illustrates the impact of driving style on the high-voltage battery’s charge level.
The charging software from the BMW i4 and BMW iX models has been further refined for the new BMW i7. Once the high-voltage battery reaches a higher charge level, the new charging process aims to ensure the charging rate drops smoothly instead of following the previous “stepped” curve. This produces a more rounded charging curve overall, resulting in shorter charging times. Following an initial, temperature-dependent phase of constant power supply, the new process now also controls charging based on a continuous nominal voltage curve that makes allowance for the variables of temperature, recharged capacity, and charge level at start of charging.
An optimized cooling strategy while DC charging is in progress further improves the durability of the high-voltage battery. Alternating phases of full and partial cooling power are used during fast charging of the BMW i7 to avoid excessive cooling of the battery. This prevents cell temperatures from dropping too low in the process, particularly at higher charge levels, thereby opening up potential for short charging times and reduced ageing of the high-voltage battery’s cells.
The Combined Charging Unit in the BMW i7 xDrive60 allows AC charging at a rate of up to 11 kW, while DC power can be taken on board at a rate of up to 195 kW.
For three years, owners of the new i7 xDrive60 will enjoy unlimited charge sessions at Electrify America charging stations across the United States at no cost.
Base MSRP for the 2023 740i is $93,300 + $995 destination; 760i xDrive $113,600 + $995 destination; i7 xDrive60 $119,300 + $995 destination. US market launch to commence in Q4 2022. Pre-orders for the i7—which are now open —require a $1,500 deposit.
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