GENEVA MOTOR SHOW: BMW presents new X4

The answer to the question nobody asked is back again, with BMW set to launch the second generation of its mid-size X4 coupe-crossover.

Dubbed a Sports Activity Vehicle by BMW, the original X4 received surprisingly good reviews, with solid engineering underpinning its junior X6 liftback styling.

Effectively a more design-focused version of the X3 SUV, the second-generation X4 will be bigger than the original, growing by 81mm to measure 4752mm from bumper to bumper.

It should also be bigger inside, with a 54mm stretch in the wheelbase to 2864mm and BMW has added 37mm to the overall width (now 1918mm) as well.

It's roughly the same height as before (the highest point is just 3mm lower at the 1621mm roofline), but the overall theme is a more mature overall design, adopting the slightly hexagonal wheel-arches of its larger siblings.

It also comes with the coffee shop show-off tech, with an optional 2.2-inch touch-screen display on the car key.

A technology that made its debut on the 7 Series, the key can be used to lock and unlock the car, close or open its windows or crank up the heating whenever it's not being used for simply showing off.

BMW has shifted 200,000 X4s since its 2014 launch, which isn't bad for a bonus SUV/crossover off the X3's solid underpinnings.

It will arrive in October with a wide array of powertrains, too, starting with the 2.0-litre four-cylinder 135kW xDrive 20i all-wheel drive and topping out with petrol and diesel versions wearing the M40 badge.

The quickest of them, just, will be the X4 M40i, with its 265kW/500Nm turbocharged straight-six petrol engine pushing it to 100km/h in 4.8 seconds.

Like its predecessor, the M40i uses the same N55 engine as the M2, with the only significant change being a different oil system (on the assumption that it will see less track time than the little coupe).

It has the same power and torque outputs as its predecessor, too, but somehow manages a 0.1sec improvement to 100km/h, while being limited to the same 250km/h top speed.

BMW has yet to declare a weight for its fastest car, but it's sharing the same architecture as the critically acclaimed new X3, so it could be up to 50kg lighter than its 1840kg predecessor, which could pull it down in the high 1700kg bracket.

It's also supposed to a 10 per cent better in aerodynamic efficiency, pulling the coefficient of drag down to 0.30Cd, which BMW claims is class-leading.

But the turbo-diesel M40d won't be a slouch, either, covering the same territory in 4.9 seconds - just 0.1sec slower than the petrol-powered version.

A far bigger difference between the two is the fuel consumption. The M40i uses 9.0L/100km on the NEDC cycle (0.1L/100km worse than its predecessor), while the M40d pulls that down to 5.4L/100km.

But the meaty slice of the X4's sales won't have the letter 'M' anywhere near it, except on its optioned-up suspension and trim packages.

A pair of four-cylinder petrol motors and another pair of four-cylinder diesels (all of which will use turbochargers for their 2.0-litre capacities) will shoulder the heavy lifting.

They are particularly techy things, with the petrol variants using twin-scroll turbochargers, direct fuel-injection, variable valve timing and lift and variable camshaft control. There are even particulate filters, even for the petrol engines.

The oil squashers squirt the diesel into the combustion chambers at up to 2500 bar of pressure to help them meet EU6 emissions regulations, along with an oxidation catalyst, an NOx absorption catalyst, an SCR catalyst, AdBlue injection and a particulate filter.

While the base xDrive20i gets by with 290Nm of torque from 1350rpm, the step up to the xDrive30i sees that jump to 350Nm, along with 185kW of power, from essentially the same 2.0-litre engine.

That step up in output helps slash two seconds from the base car's sprint to 100km/h, getting the 30i to the mark in 6.3 seconds.

Surprisingly, even the xDrive20d is quicker than the base petrol engine, with the entry-level diesel sliding beyond 100km/h 0.3sec faster, at eight seconds.

The petrol-powered entry car claims some small measure of revenge in top speed, besting its diesel sibling in the rarely visited measurement by 2km/h, with 215km/h.

But it plays a definite second fiddle to the 20d in fuel economy, with the entry diesel confirming its standing as the most economical X4 with 5.6L/100km on the NEDC cycle (for 142g/km of CO2).

By contrast, the entry-level petrol motor uses 7.3L/100km (identical to the more powerful 30i) and emits 163g/km.

There will eventually be two other diesels, though BMW will launch the car with only the xDrive25d as the next-step version.

Using the same core 1995cc engine as the 20d, the 25d will crunch out 500Nm at 2000rpm (in an unusually peaky arrangement for a modern diesel) and deliver a healthy 170kW of power.

That will haul it to 100km/h in 6.8 seconds, even though it only uses 0.1L/100km more than its entry-level stablemate.

BMW will add an xDrive30d later this year for Europe, with an inline six-cylinder turbo-diesel thumping out 195kW of power at 4000rpm and a brutal 620Nm of torque from 2000rpm.

Looking like the family's performance/price sweet-spot, the 30d will hit 100km/h in 5.8 seconds and has a top speed of 240km/h, yet returns 6.4L/100km/h on the NEDC.

All of the powertrains use all-wheel drive (eschewing modern trends towards front- or rear-wheel drive entry models), and all of them use eight-speed automatic transmissions.

Added to that, everything beyond the entry-level models have launch control (for some reason) and they can all switch between Sport, Comfort and Eco Pro modes. BMW adds a sharper Sport+ mode to the six-cylinder models and the faster 30i.

Inside story

The major criticisms we had of the 2014 X4 were its limited rear headroom and, especially, the obvious cost cutting and cheap materials used i obvious places around the cabin.

BMW has tried to correct some of those points, making LED head and tail-lights, twin exhaust tips and making 19-inch alloys standard across the range.

The front seats have been redesigned, though BMW has not mentioned any updates to the X4's particularly flat and uncomfortable rear seats, except to say its passengers now have 27mm more knee and leg room.

It has added knee pads on the both sides of the centre console for the front seats, six mood-lighting interior colours and what it claims to be "more premium" materials throughout.

It also scores a built-in SIM card and BMW's latest generation iDrive for the infotainment system. That system is now based around a 6.5-inch display atop the dashboard, while an optional Professional navigation setup pushes that out to 10.25 inches and adds a touch-screen function.

There have been steps forward in the voice-control system to allow more real-world questions, plus a gesture-control option, while the X4's optional head-up display is 70 per cent larger and now is much clearer, with 400x800 pixel resolution.

Its connectivity includes both Android Auto and Apple CarPlay, while drivers can choose which interface to use on its Open Mobility Cloud platform. It encompasses everything from the Apple watch to smartphones to Amazon Alexa or Google Home voice-controlled personal assistants.

There's a bunch of interior options, too, including active ventilation, three-zone climate control air conditioning (complete with a choice of eight scents) and a 924mm x 890mm two-piece glass roof.

The luggage area retains its 525-litre capacity, though it can rise to 1430 litres if the 40:20:40-split rear seat is folded flat, either from the seat or remotely from the boot itself. Drivers can also individually adjust the three backrest angles to manage odd cargo sizes.