Six wheels. Two seats. One horsepower. Rear-mounted hybrid powertrain. Top speed: 28 miles per hour.

It's the future of green transport. Maybe.

In April 2006, Iranian engineer Hadi Mirhejazi began working on what he calls the Naturmobil, a vehicle powered by a single horse trotting on a treadmill inside a clear plastic fuselage.

It's actually a hybrid of sorts. The motion of the treadmill acts as a generator to recharge a battery pack; that in turn powers an electric motor that propels the vehicle, through a transmission containing no fewer than 20 gears.

For the PETA members among our readership, rest assured that Mirhejazi says he has kept the comfort of the 1-horsepower "engine" first and foremost in his design. The horse is covered in a jacket of cool water, and waste is collected in a large bag below the treadmill.

At the moment, the vehicle is limited to side roads and cool climates.  The original plan was to host advertising on side-mounted LCD screens (also powered by the treadmill) and take a trip around the world. As the Guardian notes, "Alas, the plan never came off."

Now the inventor appears to be offering the prototype vehicle, the patent, and $100,000 to anyone who can satisfactorily explain why he invented the Naturmobil. That competition seems a bit rigged, since he's the only person who should (theoretically) know, but hey.

Spoiler alert: The site itself says, Naturmobil was designed to provide an innovative way of advertisement that supports tourism yet still caring for the safety of our environment. This vehicle provides the world the alternative ways of having the comfort of modernization in advertisement and still protecting the environment.

Ummmm, okay. Later on, it also says:

Naturmobil, in its own distinctive way, was designed to achieve both growth in economy and protection in the environment. Besides its modern and state-of-the-art attributes, the first and foremost consideration and the most important factor in the invention of Naturmobil is to provide smooth mobility without threat to the environment. Naturmobil is the only vehicle that can run without the use of oil.

There must be something about large ungainly vehicles, horses, and crazy engineers, though. Just last month, we covered the latest pony car built by a company with its roots (hooves?) in the famous Roush Mustang tuning shop for a client in Turkey.

You get extra points if you can figure out what this one does, with only the photo, before you click on the story link.

UK-based Revolve Technologies developed this vehicle -- can you figure out what it is?

UK-based Revolve Technologies developed this vehicle -- can you figure out what it is?

Naturmobil 1-horse-power vehicle

Naturmobil 1-horse-power vehicle

Naturmobil 1-horse-power vehicle

Naturmobil 1-horse-power vehicle

Naturmobil 1-horse-power vehicle

Naturmobil 1-horse-power vehicle

[Guardian]