Rumours of the death of the SUV may have been exaggerated. Economic and ecological conditions couldn’t be much worse for these large, expensive, thirsty vehicles, as highlighted by BMW’s cancellation of its planned X7 large off-roader and GM’s decision to sell its Hummer brand. But this month we’ve driven three SUV prototypes, each suggesting that this controversial class of car might have a future. Two of the prototypes aim to make SUVs greener, and we’ve been granted early access to them because their makers want to communicate to customers, shareholders and governments how hard they’re working on new propulsion technologies. But the first — and the first to go on sale — is an utterly unreconstructed gas-guzzler. 


BMW’s M (for motorsport) division has long produced low-volume, high-performance versions of the firm’s sports and saloon cars, characterised by their high-revving engines and scalpel-sharp handling. But now, BMW is about to put the fabled M badge on an SUV for the first time with versions of its controversial, coupe-like X6 and its more conventional X5. 


Not only is it risking the M division’s credibility with the absurdity of putting the Motorsport badge on a pair of 2.2-tonne off-roaders, but it’s abandoning, at a stroke, all the attributes that have, until now, defined an M-car: a bespoke, naturally aspirated engine, a manual gearbox and rear-wheel drive. Cue horror from the M-obsessives. Instead, from November, an estimated €90,000 will get you a 550PS, twin-turbocharged, 4.4-litre V8 closely based on the standard car’s six-speed automatic gearbox and the same four-wheel drive system, but recalibrated to send more torque to the rear axle to mimic the agility of M’s rear-drive cars. 


We drove disguised prototypes of the X5M and X6M at BMW’s Arctic test centre in northern Sweden. M has compromised its principles, but not its performance. Mechanically almost identical under the skin, these cars are brutally, shockingly fast, hitting 100km/h in a supercar-standard sub-five seconds. The low-end grunt of the turbocharged engine feels more blue-collar than the aristocratic engineering we’re used to from M, but it’s necessary to get this lump moving at M-standard speed. And out on BMW’s frozen lakes we were able to indulge in the kind of long powerslides that have long entertained M drivers.


So why risk BMW’s increasingly green image with a car so contrary to the zeitgeist? Money. BMW’s profits have been hit hard by the recession, yet the launch of the new M3 in 2008 gave the M division its second-best year ever. It needs another new M-car this year, and its SUVs were the only candidates; the purists will just have to live with it.


Next to launch will be Volkswagen’s Touareg Hybrid. We tested a prototype version of this new, high-powered petrol-electric drivetrain installed in the current version of VW’s big SUV, but it will go on sale first in the next-generation Touareg to be launched at September’s Frankfurt motor show, and then in the new version of Porsche’s Cayenne SUV and its new Panamera saloon. It’s a hugely significant new engine, not only for the number of important cars it will power, but also for the closeness with which VW has worked on it with its new controlling shareholder Porsche. VW’s long-time stablemate Audi will get a modified version of this engine for its next Q7 SUV, but hasn’t been as intimately involved in its development.


Volkswagen admits that it is late to the hybrid party, but its first effort is hugely convincing. Alone, the supercharged V6 petrol develops 328PS but the electric motor can boost that to a prodigious 369PS, or it can power the car alone, silently and emissions-free for nearly 2km and at speeds of up to 50km/h. Making the petrol and electric motors integrate seamlessly is difficult, and getting it right gave Toyota-Lexus its long-held advantage in hybrids. But VW has at least matched its Japanese rival for refinement, and also produced some impressive figures. The 2.4-tonne Touareg will hit 100km/h in 6.8 seconds and tops out at 250km/h, yet its economy and emissions figures both beat the current Touareg’s smallest, most frugal diesel option.


Downsides? A likely €4,000 premium over such a diesel when the Touareg hybrid goes on sale next year, and an extra 175kg in batteries and electric motors, partly compensated for with the loss of the low-range gear option, which will limit the hybrid’s performance off-road. Not that many ever stray off-road, of course.


Our final SUV-of-the-future really does belong to the future. The GM HydroGen4 won’t make production until 2015, and that’s assuming General Motors survives that long. Despite its current cashflow crisis, GM will build 100 of these prototype fuel-cell SUVs at a cost of around €500,000 each to see how they cope in real-world use. Much of the development work is being done by Opel in Germany, and 10 will be loaned to businesses in Berlin, which has small, experimental, government-sponsored network of filling stations equipped to provide the hydrogen these cars require.


Fuel cells work by combining compressed hydrogen with atmospheric oxygen to produce a current that powers the electric motor, with water as the only by-product. They can’t yet be mass-manufactured at a reasonable cost, but GM believes that day is coming. When it does, you’ll be able to refill your car as quickly and drive as far as you do now with petrol or diesel, giving fuel-cell cars a major advantage over battery-electrics. 


Most carmakers have fuel-cell prototypes but this is, by some margin, the most advanced we’ve driven. It will cover 300km at speeds of up to 160km/h, and despite weighing around two tonnes it accelerates to 100km/h in 12 seconds; easily enough for normal use. Most importantly, it looks and drives like a normal SUV, other than its eerily silent running and the immense smugness brought on by knowing you’re emitting nothing but steam from the exhaust pipe. By installing the large hydrogen tanks into a larger, more accommodating SUV bodyshell cabin space is preserved.


Frankly, before we drove the HydroGen4, we were a little cynical about hydrogen’s chances of being the fuel of the future. But such a practical, usable prototype makes it seem more likely. If GM can survive and get this car into production it will make the Touareg hybrid look old-hat, and the X6M look like a dinosaur. However, while the resulting vehicle will be squeaky clean at the point of use, its green credentials will still rest on the source of energy for creating the hydrogen in the first place.