BMW i4

Rear view

The production model is based on the modular CLAR platform to keep costs low and volume-production attainable.[10] Although it is described as a battery-powered G20 3 Series, the model uses the bodyshell design of the G26 4 Series Gran Coupé.[11][12][13] The i4 has a MacPherson strut front suspension and multi-link rear suspension with rear air suspension as standard (the M50 adds adaptive M dampers).[14] It has a damping system designed to reduce “dipping movements of the body” under acceleration or braking, with an “actuator-related wheel slip limitation” system to better boost traction and stability.[15]

The i4 has an almost completely flat underbody, resulting in a low drag coefficient of 0.24 for the eDrive40 and 0.25 for the M50.[16] Compared to the G20 3 Series, it has 26 mm (1.0 in) wider front tracks and 13 mm (0.5 in) wider rear tracks.[17] Due to the low floor location of the battery pack for better agility,[18] the M50's center of gravity is 34 mm (1.3 in) lower than the G20 3 Series and 53 mm (2.1 in) lower in the eDrive40.[19] An active air flap control at the bottom of the grille can be adjusted in ten stages, allowing cooling air to be supplied to the drive system, battery, brakes, and air conditioning system in precise quantities.[16] The eDrive40 has a 45:55 weight distribution, while it is 48:52 for the M50.[20]

The electric drive component of the i4, its charging unit and high-voltage battery are all developed in-house by the BMW Group, forming the fifth-generation eDrive system.[21] A notable technical feature of the i4's powertrain concerns its packaging. The electric motor, transmission and power electronics are all contained in a single component, which allows for a higher efficiency of energy conversion.[22] BMW also focussed on reducing the number of rare earth materials in the battery and electric motor system. None are used to construct the motor (efficiency factor of 93 percent),[18] while the battery uses two thirds less cobalt than before.[10] The motors themselves are positioned in the axles, and the axles also house the one-speed transmissions.[18]

M50 with the M Sport Package Pro.

The M50 can recuperate braking energy at a max rate of 195 kW and 116 kW for the eDrive40.[23] The three adjustable regenerative braking levels includes a robust setting for one-pedal driving, while the fourth adaptive mode uses GPS data and driver-assistance systems to adjust the amount of regenerative braking.[24] The eDrive40 is a rear-wheel drive model, where power comes from a single 250 kW (340 PS; 335 hp) electrically excited synchronous motor that is fitted to the rear axle.[17] The M50 runs predominantly in rear-wheel drive mode, conserving energy and thus increasing range. The larger 230 kW (313 PS; 308 hp) electric motor resides at the rear, while the smaller 190 kW (258 PS; 255 hp) only kicks in when the front tires require power.[25] Using a pre-warmed battery, consumption can be 20kWh/100 km driving in winter mountains.[26]

The 108 mm (4.3 in) tall battery in the i4 is made up of four modules with 72 cells each and three 12-cell modules,[16] which is located in the floorpan in a process that's claimed to add rigidity to the overall structure.[27] The battery enclosure is directly connected to the front axle subframe, while the battery pack is bolted to the floor assembly with 22 bolts.[18] There also is an additional section of the battery housed within the center tunnel in the place usually taken up by a driveshaft.[28] The battery voltage is between 400 volt (empty) and 477 volt (full), with a nominal voltage of 430 volt.[26] The i4's battery has 40 percent more energy density than the 120 Ah version of the BMW i3.[16]

The fifth-generation eDrive system supports up to 205kW DC fast charging. The battery pack can be charged to 80 percent in 31 minutes or ten minutes for a range of 164 km (102 mi) in the eDrive40, and 140 km (87 mi) in the M50.[29] Using a Level 2 wall box with AC power and a charging rate of 11 kW, the i4 can recharge its battery from 0–100 percent in under eight hours.[18]

The i4 features an integrated heating and cooling system that takes into account various factors such as ambient temperature and mid-journey fast-charging sessions to precondition the temperature of the battery pack. It does this automatically via high efficiency pumps that can increase range efficiency by up to 31 percent when driving in urban traffic.[17] Without pre-warming, the battery may be restricted to 75 kW charging at cold temperatures.[26]

The BMW i4 in its standard European configuration received 4 stars from Euro NCAP in 2022.[38]

The BMW i Vision Dynamics provided the design inspiration for the i4.

The initial BMW i Vision Dynamics concept debuted at the 2017 Frankfurt Motor Show,[40] and was built on the flexible CLAR platform rather than a carbon-fibre structure as with the contemporary i3 and i8 electric models.[41] The i Vision Dynamics concept gave a hint at BMW's intention to make a mid-sized EV four-door coupé.[42] It was powered by a single electric motor on the rear axle. The car had projected performance figures of 0–100 km/h (62 mph) in 4.0 seconds, and a top speed of over 200 km/h (124 mph). BMW's range goal for the i Vision Dynamics was 373 mi (600 km) on the European WLTP cycle. The design of the i Vision Dynamics was based on the study Vision Next 100 from 2016.[43]

Although the interior was not finished, BMW promised a great view outwards via the "flush integration of glass into the main body".[44] Controversially, the i Vision Dynamics featured a reworking of the double-kidney grille that covered a plethora of sensors.[45] Depending on the legal environment, BMW intimated that the goal was to launch the production car with the capability to work at Level 3 or Level 4 autonomous driving, which require differing types of human input depending on circumstances.[40]

The production version was announced at the 2018 Geneva Motor Show as the BMW i4.[46] At the 2018 Paris Motor Show, BMW confirmed the launch year for the i4 as being 2021.[47]

The headlight design was introduced in 2022 on the G70 7 Series and the facelifted G07 X7, while the rear light design was adopted in 2019 on the F44 2 Series Gran Coupé and G06 X6.

The BMW Concept i4 was presented in March 2020 and reiterated a lot of i4's specifications that was shared at the LA Auto Show in November 2019. The design language of the Concept i4 was more closely resembled to the production model than the i Vision Dynamics, and confirmed the i4 as an all-electric version of the G26 4 Series Gran Coupé.[48] The single rear-motor was projected to be rated at 390 kW (530 PS; 523 hp) that was on par with one of BMW's V8 combustion engines, though media doubted this claim as V8's are connected to a xDrive system.[49] It was clarified that the i4 would come with an EPA-estimated range of 435 km (270 mi) from an 80 kWh battery pack,[48] though the production model has an EPA-rated range of 483 km (300 mi).[50]

The BMW Concept i4 was an evolution of the Vision Dynamics.

The BMW Concept i4 was an evolution of the i Vision Dynamics design study from 2017. The proportions were classic coupé, featuring a long wheelbase, fastback roofline and short overhangs. The exterior design had been kept simple with its smooth lines and clear surfaces "as a deliberate counterpoint to the dynamic flair of the driving experience". The covered kidney grille served primarily as an "intelligence panel" housing the various sensors for autonomous driving.[51]

The concept featured a stretched wheelbase with BMW claiming it would offer plenty of cabin space.[52] The highly futuristic and minimalistic interior was dominated by the BMW Curved Display that was angled toward the driver, featuring the newest BMW Operating System 8.[53] Other notable features was an all-glass roof, mixture of cloth and leather in the seats and dash with bronze and chrome fixtures, and replacement of touchpoints with crystal-like plastic.[48][32]