But I don't roll up the window and switch the air conditioner to recirculate. Instead, I take a deep breath.
It's not black, sooty diesel smoke coming from the exhaust pipe, but clean, white steam. I can't help but think this is a glimpse of the future.
The bus, built by Xcellsis, a unit of Ballard Power Systems of Vancouver, British Columbia, is powered by a fuel cell, the environmentally friendly drivetrain that many automakers are wagering will replace the internal combustion engine.
The zero-emissions ZeBus is part of a caravan of 49 alternative-fuel vehicles making their way through the desert on a 275-mile trip as part of the Michelin Challenge Bibendum 2001, a rally for environmentally friendly vehicles sponsored by the French tire manufacturer.
There will be three stops along the way. During each break, auto writers can switch vehicles. On the second leg of the journey, about 60 miles east of Los Angeles, I ditch a diesel-powered Opel and take a seat in the ZeBus.
The inside is like any other city bus - hard plastic seats, placards with ads, metal poles to grab. Nine tanks on the roof contain about 3,600 pounds of gaseous hydrogen, which powers the fuel cell that makes electricity for the drivetrain. There's enough fuel for the trip. But if something goes wrong, there's a truck full of spare parts and diagnostic equipment and a mobile fuel unit following.
Short interruptionYou would need a sharp eye to notice that the ZeBus driver has in front of him a flat-panel computer screen that flashes a schematic.
We're rolling along at about 65 mph when a beep warns the driver. He touches the screen and sees that the power levels in all of the fuel cells are dropping. The bus begins to slow.
It doesn't take long for engineers to trace the malfunction to a bad relay that shut down a water pump to a
fuel cell. The driver pulls over. Panels come off the floor, the roof and the back of the bus. The repair is made, and the bus is back on the road in about 15 minutes. The rest of the trip goes by without a glitch. The ZeBus entered the record books by going the longest distance for a fuel cell bus.
Xcellis has built and tested a small fleet of fuel cell buses in three cities and hopes to begin commercial sale within a year. If the technology is to be accepted by consumers, fuel cell drivetrains are going to have to be as dependable as the internal combustion engine.
Many of the vehicles in the Challenge Bibendum use gasoline-powered or diesel engines or are hybrids with gasoline and electric power.
The day before the trip to Las Vegas, the vehicles in the Challenge Bibendum gathered at the California International Speedway, where they were tested on the track for speed, stopping, noise and emissions.
Different strategiesVirtually all of the world's major automakers entered at least one vehicle. It was easy to see each country's area of expertise.
One exception is Ford Motor Co.'s Th!nk City, a small, pure electric subcompact with a plastic body. The car is designed for use as a city vehicle and will have to be recharged every 100 miles.
The vehicle is due in the summer with a price of about $20,000; Ford may offer the vehicles on a lease-only basis, as General Motors did with the ill-fated EV-1 electric car.
During a trip around the racetrack, the Th!nk City was delightful to drive.
More than that, the dull finish on the thick plastic body panels gave it a funky, hip appearance.
The car would be ideal in gated communities and on college campuses. But Ford may have difficulty finding customers. GM was able to lease only about 700 EV-1s and similar electric vehicles built by Canada's Bombardier, and others have not sold well.
GM focuses on trucksGM, which first revealed its plans for cylinder deactivation this year for the Chevrolet Silverado and GMC Sierra in 2003, brought a near production-ready version of the truck to Bibendum.
The system performed seamlessly, cutting half of the cylinders on the 5.7-liter V-8 engine. GM engineers are projecting a 3 mpg increase in fuel economy once the system goes into production on 2004 model trucks. Bibendum also provided engineers and others with an opportunity to compare fuel cell and hybrid vehicles for performance, ride, handling and packaging. Toyota Motor Corp. and Honda Motor Co. Ltd. have the advantage.
Honda's hydrogen-powered fuel cell vehicle, the FCX-V3, made no more than a humming sound as it rolled over the asphalt.
The next version, FCX-V4, which Honda let auto writers test drive in Japan, is even quieter and can go 187 miles on a single tank of gaseous hydrogen.
GM's fuel cell efforts are being led by Adam Opel AG, which entered the Zafira.
Though the vehicle holds numerous distance, endurance and speed records for fuel cell vehicles, it sounds and feels much like a developmental vehicle compared with Honda's fuel cell vehicles. Early next year, GM plans to test the world's first fuel cell vehicle that uses an on-board gasoline reformer.
The drivetrain is in a Chevrolet S-10 pickup, and though it will arrive on the market much later than fuel cell vehicles from other automakers, it may do the most to advance the cause.
GM is banking on the premise that in order for an alternative-fuel vehicle to be successful in the marketplace, it must be easily refueled. GM's fuel cell vehicles will get their hydrogen from a blend of reformulated gasoline. GM says the powertrain should be ready for mass production by 2010.
Toyota also is working on a fuel cell vehicle with an on-board gasoline reformer, but the Japanese automaker already is producing a number of hybrid vehicles. The Estima minivan has a gasoline-electric powertrain and all-wheel drive. It delivers reasonable performance while getting the equivalent of about 23 mpg in city driving.
Kyo Hattori, a Toyota engineer, said the company is pursuing different strategies for different countries.
"From the standpoint of energy security, different countries have different energy structures and requirements. Maybe the path to higher fuel economy and greener vehicles for each automaker will be different," he said.