Montreal's transit corporation is switching to biodiesel fuel and buying hybrid buses in an attempt to green its fleet and cut carbon emissions.

All Société de transport de Montréal (STM) buses will run on biodiesel fuel by 2008, and the transition should be fairly inexpensive, said president Claude Trudel.

Bus engines can run on biodiesel fuel without requiring any modifications, and the cost of a fill-up should be the same. The STM even stands to save money on maintenance, because biodiesel is "a cleanser, so it will keep your engines and your cylinders cleaner," said spokesman Luc Tremblay.

Biodiesel has a reputation for smelling like fried food, but that won't be a problem on Montreal's buses, he added. "The guys that were working on the buses thought that the fuel did not smell as bad as it used to."

Replacing regular diesel with biodiesel in the buses would have the same impact on carbon emissions as taking 1,400 cars off the road, Tremblay said.

The STM will also put eight hybrid buses on west-end routes to test them in Montreal's harsh climate. Hybrid buses could emit 20 per cent less greenhouse gas than regular buses, making them a promising alternative for the future, Trudel said.

A greener bus fleet will help Montreal attain its goal of reducing greenhouse gas emissions by 20 per cent in the next five years.