SCOTTSDALE, AZ -- Scottsdale will begin using biofuels in many of its municipal vehicles in an effort to make its fleet operation more environment-friendly and energy-efficient, according to the East Valley Tribune newspaper. In July the city will begin using a B-20 biodiesel fuel, a mixture of 80 percent standard diesel fuel and 20 percent biofuels, in most of its 950 vehicles, Fleet Director Danny Johnson said. The city already has 148 vehicles that run on compressed natural gas and uses other alternative fuels in some other vehicles. With the addition of biodiesel, it expects to soon be using alternative fuels in about 75 percent of its fleet, up from about 45 percent, Johnson said. The new fuel mixture, which keeps engines cleaner than conventional fuels, is expected to save money in the long term by extending the life of vehicles, said Larry Person, coordinator of environmental programs. Johnson said Scottsdale has joined Phoenix, Tempe, Chandler and Peoria to explore forming a biofuels cooperative. It would enable the cities to purchase fuels at a lower overall price by buying supplies in larger quantities.