Alternative power sources for autos drive into spotlight

— -- Suddenly, alternative auto power seems close.

The big Frankfurt auto show in Germany, home of the speed-limitless autobahn, bristles with vehicles aimed more at saving petroleum than gulping it. Here in the USA, General Motors GM is about to put the largest hydrogen fuel-cell test fleet into consumer hands, and Honda HMC is gearing up to launch fuel-cell, diesel and hybrid models.

Here's a look at what's happening in the USA and what stands out at Frankfurt.

In the USA

•General Motors.

Starting in January, the automaker plans to begin loaning 100 Chevrolet Equinox hydrogen fuel-cell vehicles to people in and around Los Angeles, New York and Washington, D.C. Called Project Driveway, it involves the largest fuel-cell test fleet and will last two years.

GM will live up to its original pledge of a fall launch by putting a few of the vehicles into media test fleets this year.

The experiment is supposed to provide GM with real-world feedback on how ordinary users get along with the exotic, petroleum-free vehicles.

Fuel-cell vehicles use hydrogen gas in an electro-chemical reaction to power electric motors that drive the vehicles. Water vapor is the exhaust. The vehicles resemble ordinary Chevy Equinox SUVs, but the gasoline engine and fuel tank are replaced by fuel-cell hardware.

Because there are only a handful of hydrogen stations in the USA, GM is providing temporary filling sites that can pump the hydrogen gas at 10,000 pounds per square inch, packing more into the vehicles' fuel tanks to provide a longer driving range than possible with the 5,000-pound pressure that's typical. GM believes that 17,000 to 20,000 hydrogen stations across the USA would put the fuel within a few miles of 80% of all motorists, and within reasonable driving distance of 100%. By contrast, there are about 170,000 gasoline stations in the USA.

GM says it will provide the vehicles at no charge for about three months at a time.

GM is still choosing people to get the fuel-cell Equinoxes. You can apply at www.chevy.com. Click on "fuel solutions," then on " fuel cells."

•Honda.

The automaker continues to pledge that a sleek, four-door, fuel-cell car will go into limited production next year and be loaned or leased to individuals. It won't say how many FCX hydrogen fuel-cell cars it will produce, however. It currently has two fuel-cell cars in the hands of California residents.

Honda also says it will put a small, fuel-efficient, gasoline-electric hybrid vehicle on sale in the USA in 2009, smaller and less expensive than the Civic hybrid, but — Honda swears — big enough for a family. Honda hopes to sell 100,000 of those a year, a big increase over the 28,000 Civic hybrids it has averaged the past two years.

Late in '09, Honda has promised a four-cylinder diesel in a model it won't disclose. A V-6 diesel follows, but Honda won't give a timetable.

In Frankfurt

•BMW.

The German automaker showed a gasoline-electric hybrid version of the X6 SUV that's due in the USA next year. But BMW didn't promise to build the hybrid.

The hybrid X6 displayed at Frankfurt uses what BMW calls ActiveHybrid technology. It teams a gasoline engine with two electric motors to boost fuel economy 20% over gasoline-only drivetrains.

The gasoline X6 is to be manufactured at Spartanburg, S.C., alongside the car company's X3 and X5 crossovers.

•Hyundai.

A sci-fi-looking sedan called i-Blue is a teaser suggesting how the South Korean automaker might attempt to make hydrogen fuel-cell cars sexy. It was designed from the ground up to be a fuel-cell vehicle and escapes the packaging compromises involved in converting a vehicle from gasoline to fuel-cell power.

Hyundai says it would have a range of 372 miles, a big jump from the 186-mile range of Hyundai's test fleet of Tucson SUVs converted to run on fuel-cell power instead of gasoline. Hyundai plans 32 of those Tucson demonstrators in the USA. The car company says it will put fuel cells into mass production between 2012 and 2015.

•Mercedes-Benz.

The automaker says a gasoline-electric hybrid version of its ML 450 SUV, bound for the USA in about two years, would be the most fuel-efficient model in its class, but didn't specify fuel economy. Mercedes says it will use its 3.5-liter gasoline V-6 mated to electric motors.

The automaker also plans a so-called mild hybrid version of its S-class flagship sedan that, according to Automotive News, would use sophisticated lithium-ion batteries. They store more energy than the nickel metal-hydride batteries that today's hybrids use, and are seen as the breakthrough that could make pure electric cars practical.

Mercedes-Benz spokesman Rob Moran wouldn't say what batteries are planned for the S hybrid.

Lithium-ion batteries are expensive. They also get very hot and have to be cooled evenly and precisely to prevent a chain reaction that could ruin all the batteries in the battery pack.

If Mercedes has found a way to deal with those issues, it could give hybrid technology — and the improved fuel economy that it promises — a big boost. It also could invite development of electric-only vehicles, which could boast extended driving range on lithium-ion cells.

•Nissan.

Mixim is an electric-only vehicle that signals the company's NSANY intention to put an electric on sale in Japan early next decade and into other countries later.

Mixim uses lithium-ion batteries that are designed for rapid recharge — 20 to 40 minutes — by plugging the car into a wall outlet. One electric motor drives the front wheels, another drives the rears.

Nissan says the technology is at hand to build Mixim today, but the cost would be too high. The car would go about 155 miles on a charge and would have a top speed of about 110 mph, Nissan says.

Nissan and electric supplier NEC jointly are developing what they call laminated lithium-ion cells which can be smaller and store more energy than other types of lithium-ion batteries. The laminated construction makes it easier to cool the cells, Nissan says.