Diesel is still sweeping Europe. Hybrids are catching on in North America and Japan. But these trends are only short-term, some auto engineers say, as the industry prepares for the day the world's fuel reserves dry up.
The technology on display at the 75th International Motor Show in Geneva is a demonstration of that — nearly every automaker is showing off its latest hybrid cars, fuel cell models or electric prototypes in Geneva, along with the latest diesel options.
"Diesel is popular in Europe, clearly, but it's a short-term trend," said Laurent Aebi, a product specialist at Honda Motor Co., which was displaying its new FCX fuel cell car, powered by an electric motor that uses hydrogen as its energy source. "I give it another 10 years maximum. After that it will be the hybrid car.
"But both the diesel car and hybrid car are a transition as we head to fuel cell cars or pure electric cars."
Toyota is exhibiting its successful Prius gas-electric hybrid, while Volkswagen is featuring its new Golf Bifuel, which runs on gasoline and natural gas. GM is displaying its concept Sequel car with hydrogen technology, and Honda's FCX is being shown off on a giant podium complete with glittering water pool.
Lexus is unveiling its 270-horsepower, luxury RX400h, the first performance hybrid — which can go from 0-62 mph in 7.6 seconds. This SUV, with a 3.3-liter gasoline engine combined with hybrid synergy drive, goes on sale in June.
Currently, gas accounts for 98 percent of energy used in transport. The world consumes about 80 million barrels of oil a day, a number that continues to increase. American consumption alone is expected to grow nearly 50 percent over the next 20 years.
Estimates vary on when production will begin to decline. Some believe it is imminent, saying discoveries of oil have slowed and little is left to be found. Others believe oil will remain abundant for at least several decades and new extraction technologies will ensure plentiful supplies for a long time.
"War in Iraq, no war in Iraq. We are still looking at long-term solutions," said Yves Dubreil, vice president-deputy director of vehicle engineering at Renault.
"We the manufacturers need to be ready and find a solution for any political, economical or ecological crisis," Dubreil told The Associated Press. "The world's reserves are running out, there is no getting around that. Maybe in 100 years but probably a lot less."
Hybrid cars draw power from at least two energy sources, typically a gas or diesel engine combined with an electric motor. Surplus engine power and energy produced by braking are used to continually recharge the vehicle's battery.
Automakers are trying to convince consumers that hybrids can be just as powerful as traditional vehicles, but Dubreil says unless they save consumers money, they are unlikely to catch on.
Honda said in January that because of relatively new technology, its hybrid Civic, for example, costs about $2,000 to $3,000 more than a comparable non-hybrid Civic.
"The performance today of hybrids is not better than diesel in terms of economy, speed and power," Dubreil said. "And our problem is that we cannot change the behavior of people on our own. We can only offer them hybrid cars.
"But the hybrid is just getting started. Does it have a future? For that we need a crystal ball."
While the industry works on more economical hybrids, it says diesel remains the cleanest, most economical option.
In Europe, diesel accounts for over 50 percent of cars sold.
"There has been very rapid growth in the last 10 years," said Adriane Brown, president and CEO of Honeywell Transportation Systems, a $4.3 billion business that produces turbochargers for both diesel and gas-powered engines. "We expect that to reach 56 percent by 2010."
Diesel remains unpopular in the United States, however.
"In the United States, there has been a visceral rejection of diesel by baby boomers who were turned off by the bad performance of the first diesel cars," Dubreil said. "The high-tech X and Y generations will get attached to the hybrid idea, skipping diesel phase."
Dubreil said the hybrid is gaining popularity in congested areas like Tokyo, and in the United States monster motors can be sold guilt-free because of the power source.
"Is it only a politically correct car way of owning a huge motor car with 500hp that still spits out a ton of CO2?" he asked. "It's two-faced, but it works well in the United States."
Renault says it continues to attack the fuel problem, while supplying the current demand for diesel and gas cars.
"We're working on a hybrid, working on fuel cell, on alternative fuels, working on improving existing cars and diesel and particle filters," he said. "But we do need a drastic change."
Fuel cell cars have a ways to go before becoming widespread.
"The trouble with fuel cell cars at the moment is the limited distance and the problem of refueling. You can't get hydrogen at just any pump," said Aebi, noting that the FCX has an autonomy of 270 miles.
Electric cars now have a range of 155-185 miles.
"The day you can guarantee it will run over 300 kilometers and you don't need a fuel cell will be the big breakthrough," Dubreil said.