RTD Gives Methanol Buses High Marks : Transportation: After 1 1/2 years of improvements, the cleaner engines promise to have an increased role in fighting air pollution.

There is perhaps nothing more irritating to commuters and pedestrians than a foul-smelling diesel bus.

But after racking up 1 million miles with 30 methanol-powered buses, the Southern California Rapid Transit District said Thursday that the days of the smoking diesel may be numbered.

After 1 1/2 years of working out the bugs, the RTD said the methanol buses have dramatically improved reliability, offer better mileage and spew far less smoke, carbon monoxide and two smog-forming pollutants--hydrocarbons and nitrogen oxides.

Moreover, emissions of formaldehyde, which is known to cause cancer in humans, have been brought down through the use of an advanced catalytic converter to levels equal to or better than those from diesel buses, according to the manufacturer.

What all this adds up to is a far greater likelihood that methanol buses will have a larger role in advancing the cause of cleaner transit than previously thought possible. By the year 2010, RTD plans for all buses to be powered by some form of clean fuel, whether electricity, methanol, compressed natural gas or highly improved diesels.

It has long been known that methanol, a flammable alcohol sometimes called wood alcohol or methyl alcohol, offers a number of clean-air advantages over diesel--particularly the disappearance of the noxious black smoke.

But transit agencies have experienced persistent problems with experimental methanol buses.

When the RTD began its testing, for example, there were widespread problems with fuel injectors clogging up, and acceleration from a stop was sluggish. Now, however, the problems have been greatly reduced, the RTD said.

Fuel injector clogging was cut back by a fuel additive manufactured by Lubrizol, an Ohio company. RTD mechanics eliminated the sluggish start problem by modifying the amount of fuel delivered to the combustion chamber. This also resulted in better mileage.

“There were a lot of technical issues to overcome, but I think we’ve got the solutions,” RTD equipment maintenance director L. Rich Davis said.

The methanol bus test program, financed by a $3.4-million grant from the federal Urban Mass Transportation Administration and the Los Angeles County Transportation Commission, is being watched closely by other transit agencies around the country, as well as the state and federal governments.

Of particular interest was testing data from the engine manufacturer, Detroit Diesel, indicating that formaldehyde emissions were lower than those from diesel buses.

“That’s very significant,” said Alan C. Lloyd, chief scientist with the South Coast Air Quality Management District. “We expected the particulate emissions to be down. But the aldehydes (including formaldehyde) we were worried about. We didn’t want to see a trade-off between reduced particulate levels and elevated formaldehyde.”

Particulate matter is largely responsible for the smoggy haze so well known to Southern Californians. The microscopic particles absorb light, reduce visibility and pose a health threat to humans who breathe them.

RTD officials said Thursday they are not ready to say how big a role methanol buses will play, although they said there is little doubt that there is a bigger future for methanol than first thought.

“I think this is an excellent start. . . . I think it augurs well for methanol for the future,” said Lloyd.

The agency has a total of 2,500 buses, almost all of them diesel. Well over half are older diesels that belch black smoke; the rest are newer diesels that are somewhat cleaner. The RTD purchases 200 to 250 new buses each year to replace older vehicles.

The transit agency is examining other alternatives, including compressed natural gas and so-called “clean diesels.”

“We’re looking for the lowest cost while still providing a clean atmosphere,” Davis told reporters.

The average life of a methanol engine is 150,000 to 175,000 miles; a diesel engine will last an average 250,000 miles. Methanol engines also cost about $30,000 to $35,000 more.

Still, RTD officials said they are enthusiastic about methanol. “These are not buses in a laboratory. They are buses that are crisscrossing Los Angeles County. The results are tremendous,” said Nick Patsaouras, RTD board president.

Lloyd said it is possible that compressed natural gas buses, which are about a year behind methanol in their development, may eventually take the “lion’s share” of the transit bus market.

The drive toward cleaner buses is pushed in large part by a tough new state tailpipe standard that limits particulate emissions to 0.1 gram per mile.

The standard covers all buses built in 1991 and later and means that buses will be about 80% cleaner than they were just two or three years ago, according to state Air Resources Board spokesman Bill Sessa.

At the same time, RTD spokesman Jim Smart said public opinion has kept pressure on transit authorities to get rid of smoking diesels.

“It is definitely public sentiment. It is demanding change. They are not taking excuses, especially in Los Angeles. We have really tried to join the charge and work for clean air solutions,” Smart said.

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