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Fuel Efficiency: A really Bib show

LOS ANGELES, Calif. - How practical is the concept of alternative fuels, especially for trucks?We'll never know until they're tested on pavement, and for this there's the Michelin Challenge Bibendum. ...




LOS ANGELES, Calif. – How practical is the concept of alternative fuels, especially for trucks?

We’ll never know until they’re tested on pavement, and for this there’s the Michelin Challenge Bibendum. This annual event is a festival of sometimes whimsical, occasionally practical and always interesting vehicles.

The 2001 event in late October started with conferences in Los Angeles; continued with many entries competing for handling, quietness and fuel economy titles at the California Speedway in Fontana; and climaxed with a caravan up Interstate 15, 275 miles to Las Vegas.

Michelin sponsors the Challenge Bibendum to promote innovation and automotive efficiency.

Good tires are important to efficient vehicle operations, but novel and futuristic powertrains are the Bibendum’s main focus. Most of the entries were cars and light trucks powered by gaseous fuels, electricity, batteries or fuel cells.

Some “hybrids” used piston engines to spin generators that charge batteries that run propulsion motors.

On the drive down the West Coast from Vancouver, the Westport Ford Focus entry got 30 per cent better fuel economy than a second Focus with a gasoline engine, one source said. Westport has not released actual miles-per-gallon figures.

The Westport engine also performed well in economy runs around the speedway on Saturday, the company says and on Sunday made it almost all the way to Las Vegas. An aftermarket sensor failed and temporarily sidelined the car.

Westport is fitting Cummins diesels with gas-burning equipment for use in transit buses, and hopes for business from truck operators in smoggy cities.

Most of the technologies employed in the cars and small trucks are still under development for a time that may or may not come.

Moving cargo is another matter, because it has to be efficient and economical, and turn a profit in the process. Freightliner and Volvo showed vehicles designed to do this while sitting as well as while underway.

Both were equipped with Michelin’s latest product, the X-One big single tire that delivers lower weight and higher fuel economy than standard dual radials.

The Freightliner Century S/T tractor featured an experimental auxiliary power unit with hydrogen fuel cells. The APU is hung on the left side of the frame behind the sleeper.

Developed by Excellsis, a company partly owned by DaimlerChrysler, the APU generates electricity to heat and cool the sleeper, says Jim Martin, Freightliner test engineer.

The APU generates 1.5 kilowatts of electricity, which is enough to also run 110/120-volt accessories without help from the engine-driven alternator. This allows idle-free overnight stops and rest breaks, saving diesel fuel and cutting air pollution.

Hydrogen fuel cells are silent, so only a faint whirring from a pair of cooling fans was audible while standing next to the open unit. With the truck’s engine off, noise inside the cab and sleeper is cut by 15 decibels, Martin says.

A fuel cell works like a battery. In this case, hydrogen gas is combined with oxygen from ambient air; an electrochemical reaction produces electrons in the form of 28 to 30 volts of direct current. An 1,800-watt inverter converts the DC to 120 volts AC.

As a byproduct, a small amount of water is also formed; this is caught in a plastic can on the demo truck, but the pure water could drip harmlessly to the ground.

The pressurized hydrogen fuel is carried in a small tank. Hydrogen is explosive, but so are many fuels, so that’s not seen as a problem. But hydrogen is not sold at your average truck stop, and building an infrastructure would be a challenge.

So some type of inexpensive “reformer,” to extract hydrogen from diesel or other readily available fuel, would be needed. Or, Martin says, another type of fuel cell may be used by the time Freightliner is ready to offer the APU in three to five years.

Available now from Volvo is an inverter kit and a “shore power” option for running 110-volt appliances, both demonstrated on a 770 tractor at the Bibendum. Shore power includes 110-volt wiring in the sleeper and a cord that can be plugged into any nearby 110-volt outlet. Power outlets are more readily available than one might expect, Volvo people say, because they sold about 6,000 shore power kits last year.

Among operators committed to alternate fuels is United Parcel Service (UPS), which displayed three types of trucks at the Bibendum: a Mack tractor and a walk-in van that burn natural gas, and an electric-powered minivan. All run every working day and haul real packages delivered by real drivers. The Mack is a CH600 whose 12-liter diesel runs on liquified natural gas, or LNG. Its 350-hp E7 diesel was modified with the LNG fuel system that includes special plumbing, ignition system and spark plugs to fire the gas.

A pair of 150-gallon insulated tanks carry the liquid gas, super-cooled to minus 250 degrees Fahrenheit, at 250 pounds per square inch.

The single-rear-axle tractor pulls a pair of 28-foot doubles trailers from Ontario about 140 miles to Desert Center, where it swaps the trailers for two brought from Phoenix by a standard tractor, then returns to Ontario.

“The driver likes it,” said Jim Breeher, an automotive manager at UPS’s Ontario shop. “It runs smooth and quiet.” There’s also no smoke, even when starting cold, and no fumes, because only odorless LNG is burned.

UPS has 12 more LNG tractors like this and will buy more, according to Mike Herr, corporate environmental affairs manager. Tax breaks and other special incentives from federal and some state governments make their high purchase cost – about $50,000 extra per tractor – manageable, he says.

Another factor is the cryogenic fueling station, which costs $250,000 to $500,000. UPS has one in Ontario and others elsewhere, and trucks that have to be fueled from them cannot roam far. This is not a problem because UPS power units all run out of assigned terminals and return home each night.

This Mack averages only a bit over 3 miles per gallon, Breeher says. But LNG costs 65 cents to $1 a gallon, vs. $1.40 to $1.60 or more for diesel. So the cost per mile is about the same or less than for a standard diesel engine, and the cleaner-burning LNG engine should last longer.

UPS plans to buy another nine LNG tractors, according to Jill Reece, Pacific Region automotive manager. A “wish list” of changes, she says, includes more power and an electric driveline retarder. Mack diesels in UPS’s linehaul tractors are set to 355/385 hp, making the LNG’s 350 hp a little wimpy. And the diesels have Jake Brakes which cannot work with the LNG engines.

CNG is stored under 3,000-psi pressure in two 16-gallon tanks; a regulator cuts pressure to about 35 psi before it goes to a pair of throttle-body injectors on the engine. As with LNG, range with CNG is limited; the 32 gallons lets one of these cars run 100 miles, less than half the range of a diesel-powered car.

For some reason the engines’ spark plugs become fouled at 20,000 to 22,000 miles and are replaced, said Robert Hall, a corporate maintenance manager. And pressure regulars tend to fail at about 25,000 miles. GM has worked on both problems and the second generation of CNG engines should be better.

With little or no soot going into the crankcase, the oil change interval can be stretched from a gasoline engine’s 3,000 miles to 4,500 miles, said Al Freilich, a Los Angeles-based fleet manager.

We found that a P-1000’s CNG behaves a lot like it still burned gasoline. But of course it makes no fumes and is a bit quieter, Freilich said. He pointed out that the engine can be lugged quite low, which is useful in traffic. With only 122 hp and a 4-speed transmission, it’s less than a sparkling performer, but is enough for around the mostly flat city.

Maybe you’re wondering where the event’s name, Bibendum, comes from. Michelin people explained that Bibendum is the proper name of the tire-stack mascot otherwise known as the Michelin Man.

When he first appeared in 1898, he held a tumbler of nails and other road hazards that Michelin’s tires shrugged off. He raise
d the glass and declared, “Bibendum!” – literally, “imbibe,” but figuratively, “drink up!”


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