The BMW i7 is speeding through development toward series production, and is slated to be unveiled next year among an array of other 7 Series variants. Like any other BMW model, an integral part of the process involves exposing prototypes of the i7 to the extremes of nature. The cold part of the equation takes place in and around BMW’s winter test center in Arjeplog, Sweden, not far from the arctic circle, while hot-region testing is conducted in a variety of locations all over the world including tracks and public roads, both paved and unpaved.
Before any new BMW model reaches series production, prototypes are subjected to a lifetime’s worth of conditions faced by a conventional production vehicle. Some examples include prolonged exposure to extreme heat and direct sunlight, dust, and traversing primitive roads which may not be paved. During the evaluation process, sensitive onboard equipment is monitored by vehicle development engineers examining how components and systems are reacting and keeping an eye out for anomalies.
Effectively an electrified BMW 7 Series, the i7 is described as the world’s first electrified luxury sedan. Specific details as to its drivetrain have not been divulged, but we expect something similar to the systems which underpin the BMW i4 and iX, as the i7 appears to share BMW’s modular rear-wheel-drive platform. The hot-region test program takes place over tens of thousands of miles and pushes various vehicle systems to their veritable limits in extreme road and weather conditions. Systems of particular importance and interest on the i7 are the performance and reliability of the vehicle’s electric motors, the high voltage batteries responsible for powering them, xDrive all-wheel-drive, integrated cooling systems, and the drive control system which essentially makes it all happen.
Some of the specific hot-weather test environments and procedures include traversing a long incline with a substantial elevation change on a road described as dynamic, which means lots of curves, while driving down a steep grade with a battery that’s already fully charged and unable to accept any more recuperated energy is another. Prototypes of the i7 are also driven in trailer mode to increase the load on the drive system. Electric motors and more specifically batteries are particularly susceptible to fluctuations in temperature, with performance and efficiency both tending to suffer in extreme conditions. Various other systems, including the variety of electronics found in any modern vehicle, along with interior materials, are also stressed under these conditions.
It’s all to ensure that when the i7 is for sale at a BMW center near you, it’s ready to deliver the driving experience and sense of isolation such a vehicle is known in just about any practical use scenario.—Alex Tock
[Photos courtesy BMW AG.]