

With all of the Prius hybrids on the road these days and Toyota's emphasis on gas-electric drivetrains, it's easy to forget the company is a big player in hydrogen fuel cell vehicles - and it's developed one that sets a benchmark for range.

The FCHV-adv has a maximum cruising range of 516 miles on a single tank of hydrogen, more than twice the range of its predecessor and considerably higher than the 270 miles of the FCX Clarity that Honda will begin leasing to a very small number of people this summer. Toyota says the FCHV-adv has been certified by the Japanese government, and the company plans to begin leasing them in Japan later this year.

So how'd they do it?

Toyota upped the size of the storage tank from 148 to 156 liters and doubled the storage pressure to 70 MPa (about 10,000 PSI). It also increased fuel efficiency by 25 percent through improved fuel cell performance, enhanced regenerative braking and cutting the amount of energy required to drive the accessory systems. The fuel cell also will operate at temperatures as low as 22 degrees Fahrenheit below zero.

The FCHV-adv still uses a nickel metal hydride battery, whereas the Clarity has a lithium-ion battery. The two companies were the first to introduce hydrogen fuel cell vehicles in 2002, and they've been locked in a race to develop the first commercially viable hydrogen vehicle.

Although both companies plan to have the vehicles on the road - albeit in very limited numbers - by the end of the year, fuel cells remain hobbled by their high costs, which is why the vehicles are being leased. Fuel cells remain expensive to manufacture and their long-term durability remains suspect (although it is improving), and - the FCHV-adv aside - they offer relatively limited range.

Still, most major automakers are aggressively developing hydrogen vehicles. BMW is putting its Hydrogen 7 in the hands of Hollywood celebrities, General Motors promise to roll out the Equinox Cell Vehicle later this year and Hyundai says it will produce hydrogen cars by 2012. Clearly the auto industry is clearly confident that it can clear those hurdles.

That just leaves the matter of creating the fueling infrastructure...