Never let it be said that Russian billionaire Mikhail Prokhorov doesn't put his money where his mouth is.

He plans to invest 150 million euros, or about $200 million, in a new company that will build the world's first production natural-gas series hybrid vehicle.

The car will be called Yo, which is how you pronounce the letter "e" in Russian, and built by the new Russian automaking firm, to be called e-Auto.

Rotary-vane engine

Developed by several dozen Russian engineers, the Yo (known as the City Car when announced in late October) is a series hybrid. Its wheels are driven by two small electric motors, but the electricity to supply them is created by an internal combustion engine powered by either gasoline or natural gas.

Most remarkable, the combustion engine is a rotary-vane design in which pistons move in a circular path rather than up and down as in a conventional engine. It has very few moving parts, and runs smoothly due to the lack of reciprocating parts.

Yo chief engineer Andrei G. Ginzberg said the design was used in Germany in the 1930s but then abandoned, with only Soviet scientists continuing to work on it at a lab in the Siberian city of Novosibirsk.

No battery pack

The engine runs at a constant speed, which means it can be tuned for maximum efficiency. But rather than a lithium-ion battery pack as in most hybrid and electric cars, the new Yo uses a bank of capacitors to deliver extra power when needed for acceleration.

Capacitors are lightweight and can deliver high power for short periods--up to 10 seconds, perhaps--but store very little total energy. A battery pack stores lots of energy, but may be limited in its power delivery and is expensive, as well as heavy, whereas the target weight for the Yo is less than 1,500 pounds.

It's hardly high-performance, with acceleration to 60 mph in somewhere between 8 and 14 seconds. Maximum speed is roughly 80 miles per hour, but the company claims the car will return fuel economy of 67 miles per gallon.

With both its gasoline tank and natural-gas cylinders fully filled, the range of the Yo is said to be 680 miles. Prokhorov plans to put the car on sale by the middle of 2012, for a price of approximately $14,500. 

Russian domestic market

The Yo is meant to be a simple, affordable car for the Russian domestic market, perhaps in the vein of the boxy Lada Classic sedan. That vehicle is still recognizable as the Fiat 124 introduced in the mid-1960s. When it was replaced, Fiat sold the tooling to Russian carmaker Lada, which has since built more than 5 million of them.

Prokhorov showed three different Yo models at a media event: a hatchback, a coupe, and a small delivery van. At the launch event, he managed to sit in both the front and rear seats of the compact Yo. Since the Russian billionaire is 6'8" tall, it was apparently a convincing demonstration of the car's interior space.

Natural-gas cars a rarity

Toyota actually showed the first-ever natural-gas hybrid, the Toyota Camry CNG Hybrid concept it unveiled in 2008. The show car blended a natural-gas powertrain with Toyota's Hybrid Synergy Drive system, though whether it will be built or not is an open issue.

At the moment, only one natural-gas powered car is sold in the U.S. That's the 2011 Honda Civic GX, though Honda is expanding into new markets with the Civic GX and has said that it will sell the natural-gas model of the redesigned 2012 Honda Civic nationwide.

[The New York Times]