But that’s all hypothetical. For now, BMW’s goal is to be ready – readier than rivals, at least – for such an eventuality arising, and this is why the iX5 exists, albeit at a tiny scale.
Rather than being built en masse alongside every other X5 derivative at BMW’s vast SUV plant in South Carolina, the US, this hydrogen fuel-cell version is being hand-assembled in Munich, Germany, with fewer than 100 examples to be made.
They will form a pilot fleet not unlike those of the old Mini E and the 1 Series-based ActiveE field-testing models that were put into the hands of select members of the public around 10 years ago. Those cars paved the way for the genuinely ground-breaking i3, which in turn empowered BMW to launch the i4, the iX, the iX1 and now even the i7. It would take years, but the iX5 could one day prove to have played a similar, acorn-like role for future FCEVs, which BMW executives insist will be offered alongside, rather than instead of, the BEVs that have rapidly established themselves.
Our iX5 test route in and around Antwerp in Belgium was revealing insofar as it revealed absolutely nothing untoward about the fuel-cell driving experience. To all intents and purposes, this prototypical X5 feels much like a more conventional battery-electric iX5 might, and that’s down to the power delivery.
As with existing FCEV efforts, such as the Hyundai Nexo and Toyota Mirai, hydrogen is fed from those carbon-clad tanks and into a fuel-cell system (incidentally, the cells are supplied by Toyota) that separates H2 molecules into protons and electrons. The electrons form the current that powers the drive motor, while the protons combine with oxygen ingested from the atmosphere to create the car’s only exhaust product, water. The point here is that the motor is the one you will find on the back axle of the battery-electric iX xDrive50, and it behaves in exactly the same way, being smooth and responsive. Note also that the car’s rear-mounted motor is its only motor, making this the first purely rear-driven X5.
As ever, things aren’t quite that simple, at least concerning the powertrain. The fuel cell itself is capable of supplying enough draw only for about 170bhp. The rest comes courtesy of a small, high-performance lithium ion battery pack that sits just beneath the boot floor. This is constantly being topped up by electricity from the fuel cell, and when you really put your foot down, it's responsible for supplying not only that instant-feeling acceleration pick-up (if drive was delivered directly from the fuel cell, there would an ever-so-slight delay) but also the additional shove needed to see the iX5 realise its full potential of 396bhp and 524lb ft .