There are two types of hydrogen fuel available: compressed gaseous and cryogenic liquid.  The former is already powering numerous city buses in Germany.  However because of its gaseous nature, the power produced by volume isn’t much.  In fact, they require large fuel tanks (usually running the entire length of the bus’s roof) for a modest range.  On the other hand, cryogenic liquid hydrogen is more compressed and offers much more punch per volume.  BMW says 75 percent more energy is possible with the same volume and thus, liquid hydrogen can provide longer cruising range than compressed gaseous hydrogen.

So when we talk about what powers the regular looking Hydrogen 7, the answer is liquid hydrogen.  But since hydrogen filling stations are still scarce, BMW added something extra-special to make the Hydrogen 7 much friendlier as an everyday luxury science project on wheels: dual-fuel technology.  Based off the 760Li’s 6.0-liter unit, the Hydrogen 7’s V12 engine can run on either Super Premium (98 octane petrol) or liquid hydrogen.  The secret of the Hydrogen 7’s dual fuel capability lies in the modifications done to the injection valves and intake.  Aside from the hydrogen piping system, the engine’s brain has been optimized for combusting both types of fuel since hydrogen burns ten times faster than gasoline.  Since the modifications are mostly limited to fuel delivery and software; and the engine block being off-the-shelf, it means that the development time is shorter and production costs are lower than say, a fuel-cell car.  In fact, the Hydrogen 7’s engine is already produced in parallel with other petrol engines in the 5, 6 and 7 Series range at BMW’s Dingolfing engine plant.

BMW has already proven that a car running completely on an internal combustion hydrogen engine is possible with their H2R concept.  But again, since there are not much hydrogen stations worldwide, this move isn’t practical.  On the other hand, the dual-fuel Hydrogen 7 can cruise 200 kilometers on pure hydrogen and an additional 500 kilometers on petrol.  For power junkies who must know, the Hydrogen 7 pushes out 260 horsepower and 390 Nm of torque enough to propel this 2 ton machine from 0-100 km/h in 9.5 seconds and to a top speed of 230 km/h.  The power figures may seem modest at best, but remember the first V12 7 Series?  Its engine has similar power figures, but the Hydrogen 7 emits nothing but water vapor!

Back to the subject of traffic citations, according to the marketing folks at BMW, they’ve already received a couple.  And who could blame them?  We had the chance to sample the Hydrogen 7 ourselves for a good 240 kilometers, and it feels and accelerates like a regular autobahn stormer.

Starting up the car is a drama-free affair.  Simply insert the key and push the engine start button.  There’s a couple of seconds before the engine breathes to life.  It doesn’t have the best ignition sound as there’s some heavy crackling (like a deep fryer), but it must be noted that the Hydrogen 7 can only be started in hydrogen mode (better emissions versus petrol).  After everything settles in though, the V12 rests up and purrs into a nicely balanced whine.  Flick the steering-mounted gear lever and you’re off.

On the streets of Berlin, it’s impossible to fault the Hydrogen 7.  We’ve driven our fair share of 7 Series in the past, and this one behaves no differently.  “The unspectacular spectacular” as the Germans call it.  In terms of equipment level, BMW spared no expense as it’s fully loaded inside: leather-lined dash, piano lacquer trimmings, satellite navigation, double-paned glass and even the soft-close mechanism on the doors.  In fact, to tell this apart from the regular 760Li, you have to look carefully.  The only changes are a button on the steering wheel to switch fuel source, a button to open the hydrogen filler cap and the door sill plate that reads “BMW Hydrogen Power”.  It seems that clients of the Hydrogen 7 want to save the environment without sacrificing their own comfort.

The rear occupants will tell a different story though.  Since the Hydrogen 7 has two separate fuel tanks, engineers positioned the hydrogen system on top of the rear axle.  This means that some leg room was robbed from the back, making the accommodations a bit tighter, but still larger compared to a regular wheelbase 7 Series.  The rear armrest is also fixed making the Hydrogen 7 a strict four-seater car.  The position of the hydrogen tank also means that some rear visibility has been sacrificed, but not to the extent of being distracting or discontenting.  The luggage space has also been reduced to around 225 liters—or just barely enough for a round of golf.

next page >