All-electric BMW i4 gives great dynamic account on German test track
Fans of the Bavarian motorcars that all but dominate in the British company car sector are in for a future surprise, explains a satisfied Iain Robertson, who has been privy to a behind-the-scenes exercise that reinvigorates his marque enthusiasm.
We are truly fortunate with several model pre-launch activities, in which we have participated over the years. Given the opportunity to sample a new model that has not yet been revealed to the public is a tremendous privilege, of which I am only too aware. While the final details are disguised carefully by a camouflage wrap externally and fabric covers in the cabin, because BMW wants us to neither gain advance knowledge of a revised dashboard layout, nor what the front radiator grille is going to look like, to all intents and purposes, what you can see in these pictures is the entirely fresh i4 that is set for UK introduction later this year.
The reason for a trip to Germany lies in available track time at BMW’s test circuit, which is a comfortable distance away from any major conurbations. Besides, we are not testing a new car, although we are being given a masterclass in vehicle dynamics – the science of enabling a car to be driven at speed, without falling over. Of course, a secondary reason lies in the amount of ‘not so positive’ comments made about the on-road behaviour of some of BMW’s extensive range of models, which it hopes to correct with the next generations.
From a personal viewpoint, as the i4 is the next link in BMW’s electrified chain, I was keen to experience how the firm’s chassis engineers might remedy an interminable problem related to battery-electric cars; they handle like pounds of mince, or in BMW’s specific case, finest Kobe beef mince. In all this mad rush to get EVs to market, before the fossil-fuel shut-off date (‘E-Day’) in 2030, regardless of whether the brand is Porsche, or Nissan, none of them can truly compete with the Laws of Physics.
Even adopting a clean-sheet approach (rather than converting existing models), slapping a large and weighty battery pack between the front and rear axle lines and then compounding the issue by installing one, or more, electric motors, which are anything but lightweight, to drive the wheels, causes a dynamic nightmare. Naturally, the better players have done what they can to lower the centre of gravity, which effects the polar moment of inertia, as a means to control body-roll and lateral sway. However, even the most sophisticated of electronic stability and traction control systems, allied to lateral G-sensors, can be defeated, if not on a bone dry and grippy surface, then in adverse weather conditions, when the driver needs to gain control.
Having to contend with two pressure fronts, BMW’s team has really gone to town with the i4. “For the first time, we’ve developed a BMW with sporty DNA for purely electric driving entirely from scratch,” explained project manager, David Camacho. “The BMW i4 offers everything that BMW stands for and it’s fully electric, too.”
Only a few months prior to its world premiere, the i4 is completing the final phase of driving dynamics testing. David’s focus is on the integrated application of all drive and suspension components, to ensure that the instantaneous power delivery of the electric motor is combined with precise, controllable handling in every situation. This includes an engaging cornering stance, optimised traction in any climatic and road conditions and perfectly balanced ride comfort.
While a heavy reliance is placed on sophisticated and ingenious electronic management systems, even a brief drive of the new BMW i4 reveals an intoxicating blend of maturity and a fun driving experience that I am yet to sample from its rivals, although the latest Porsche Taycan is immensely impressive. The i4 being experienced is powered by a 530bhp electric drivetrain that can sprint from 0-60mph in around 3.7s, to a maximum velocity of 155mph. Put into perspective, that is more grunt than the V10 M5 model of the mid-noughties…but the kerbweight is nudging 2.4tonnes.
While I expected some ‘nodding donkey’ reactions, the automatically adjustable suspension damping, allied to actuator-related wheel slip restriction, removes tail dip during harsh acceleration and even front-end dive under braking conditions. Forcing the i4 to endure a coned slalom that also tests its roll control, the results are eye-wateringly phenomenal.
Let’s face it, any mid-size family car that can lambaste acceleration repeatedly like a supercar is going to be impressive but, when its cornering agility, complete with commensurate ‘feel’ at the steering wheel and in the driver’s seat base, makes even a seasoned test driver reassess his knowledge base, the need to intake gulped air several times, is the only way to make the brain react. No matter how speedy are the steering inputs, the car’s high-geared and perfectly weighted Servotronic power steering follows instructions to the letter, tantalisingly and without hydraulic delay.
The upshot is superior chassis balance and unerring agility that all but ignores whatever Archimedes taught. The long wheelbase of the i4, which is accommodating to the lithium-ion battery pack, provides the additional benefit, not felt on many of BMW’s competitors, of a deliciously leggy ride quality. The width of the vehicle’s track, i.e. the distance between either end of the axles, wheel-to-wheel, ensures the magical combination of cornering stability and all but roll-free progress. David explained that there are model-specific camber and castor values, which are also dependent on different alloy wheel diameters and the tyre profiles, which will limit domestic customisation of the i4, as dealer recommendations will impact on optional wheel choices, which may demand suspension geometry changes.
All parameters and variables are being taken into account during the final testing of the i4, to ensure integrated application of the drive and suspension components, all with BMW’s sporty hallmark in mind. At the same time, the virtually silent drive, in combination with the advanced suspension technology and more rigid structure, gives an impression of effortless progress even at higher speeds, that are entirely unaffected by bumps in the road, or difficult traction conditions.
Conclusion: BMW has passed the acid test. It feels as connected as a Porsche Taycan, if not more so, in fact. The company is conscious of a need to return to its former ‘Ultimate Driving Machine’ tagline and I believe it has achieved it.