TORONTO, Ont. – Natural gas vehicles may be taking off in some areas of Europe, but for North American heavy-duty engine manufacturers, diesel is still the way to go.

This was the overwhelming message delivered by heavy-duty engine manufacturers and customers at the Windsor Workshop Transportation Technology and Fuels Forum recently held in Toronto.

The annual Natural Resources Canada event, cancelled last year due to poor attendance (a.k.a. SARS), was back this year with a full complement of technocrats and transportation industry insiders from all four corners of the earth, eager to sell co-delegates on their particular brand of technology and/or fuel.

But nothing came closer to the core of North American trucking than the no-holds barred statement of panelist John P. Walsh, chief maintenance officer for New York City Transit’s Department of Buses.

“Heavy-duty trucking is what drives the bus market in North America,” said Walsh, “And heavy-duty manufacturers have made it clear they’re not interested in alternative fuels (natural gas).”

Walsh pointed out natural gas vehicle sales have declined in the North American market, making research and development dollars scarce.

“There was an initial promise that running natural gas vehicles would become less expensive and more efficient over time, but that has yet to happen,” said Walsh, whose fleet participated in trials testing natural gas engines against others, including EGR engines with particulate filters.

“Natural gas vehicles have exactly the same problems in the long term as cooled EGR engines with filters. Don’t let anyone tell you different.”

Warren Slodowske, manager of emissions certification and compliance for International Truck and Engine Corporation agreed. (“Certification” means the engine maker is allowed to make the engine to put on the road, but it doesn’t necessarily “comply” with EPA standards. The manufacturer “pays” for not complying with credits earned via other U.S. Environmental Protection Agency initiatives.)

“The term ‘clean diesel’ is not an oxymoron,” said Slodowske. “And although natural gas may have a temporary advantage when it comes to producing fewer NOx emissions, that’s not true for particulate matter. So, overall it’s probably producing about the same amount of emissions as low emitting diesel, and low emitting diesel will probably produce even fewer emissions than natural gas in the near future.

“There appears to be a race on to crucify and villainize diesel, but most of the studies that back this sort of thing up are due to bad science,” Slodowske said.

He pointed to a study that showed diesel emitted 41 toxins and claimed a counter-study commissioned by International “found only 21 of the toxins scientists were claiming had been found in diesel.”

And Slodowske went on to point out the difficulties of selling natural gas vehicles in the North American market, due to a lack of dispensing infrastructure, but even more importantly due to security and liability issues.

“Find me a fire department that has a natural gas truck!” he challenged audience members.

His challenge elicited a comeback from one audience member, who pointed out the same safety issues can be raised regarding hydrogen-powered vehicles.

Still, the natural gas solution is proving useful outside North America, particularly in markets where natural gas is more easily available and therefore less costly than diesel.

“Our largest customer for natural gas vehicles is China,” said Vinod Duggal, director of strategic planning and advanced engineering for Cummins.

“Our second largest NG customer is India. The technology clearly has a role to play worldwide, but volume isn’t driving natural gas vehicles in North America.”

(For the North American market Cummins, like International, will produce cooled EGR engines with particulate traps to meet 2007 emissions standards.)

As for Europe, natural gas vehicles are gaining popularity in colder climates, where SCR’s additive (urea) can freeze.

Nils-Olof Nylund of Tech Transenergy Consulting Ltd. pointed to natural gas city buses currently running in Helsinki, Finland.

“How do you run an SCR engine when it’s minus -11 C in Finland?” he asked.

Natural gas has also made inroads in France, where nuclear power is the mainstay for home heating and electricity.

Ultimately, local resources will drive technology, panelists agreed, making the likelihood of natural gas vehicles in North America improbable. At least until the oil runs out.