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Metro Transit leads with use of biodiesel fuel

Five percent content exceeds state regulations, and higher content tests are under way

Bolstering its record of providing transit service in ways that are friendly to the environment, Metro Transit in July began fueling all its buses with “B-5” — a diesel fuel with five percent biodiesel made from soy. The agency is the first large diesel operator in the state to use the fuel.

“Biodiesel has the benefit of being a renewable resource with lower emissions,” said Brian Lamb, general manager of Metro Transit, “and we’ve gone beyond the state requirement that all on-road diesel fuel sold in the state be mixed with at least two percent biodiesel.”

Metro Transit’s action came following extensive testing of B-5 on several buses. Mechanics measured vehicle performance, fuel mileage, cold weather operation, and fuel stability, quality and shelf life, and analyzed engine oil. They learned that a five-percent biodiesel fuel mixture had no negative effects on bus engines and did not present cold weather operating issues.

Going the next step: testing B-20 biodiesel

Now the agency is taking another step forward and is testing what is known in the industry as “B-20.” Starting in July and running through February, workers will test on 10 buses a fuel with 20 percent biodiesel content. They will monitor performance using the same protocols used in the B-5 experiment.

Engine manufacturers have been cautious about using a higher percentage of biodiesel than B-20 because cold weather could stop the fuel from flowing properly, according to Lamb. One of Metro Transit’s tests will be to see what level of biodiesel can dependably run in cold weather.

“The effort to test biodiesel fuel is important because this fuel is a growing component of America’s renewable energy supply to reduce dependence on foreign oil,” Lamb said. “It also results in cleaner air and a better environment.”

In 2005, Metro Transit was a leader in adopting the use of ultra-low-sulfur fuel for its buses more than year before a federal mandate went into effect. Ultra-low-sulfur diesel fuel is a specially refined diesel fuel that has dramatically lowered sulfur content (15 to 30 parts per million of sulfur compared with 500 parts per million for low-sulfur diesel) and thus, cleaner emissions.