title of chief executive officer on October 30, 2001, following the ouster of then-CEO Jacques Nasser. With the retirement of Ford president and chief operating officer Jim Padilla in April 2006, Bill Ford assumed those roles as well. On September 5, 2006, Ford announced that he was stepping down as president and CEO, naming former Boeing senior executive Alan Mulally as his replacement. Ford continues as the company's executive chairman. At the time of his stepping down, Ford was ranked 264th on Forbes''' list of top-earning CEOs, at $10 million per year. Business developments In 2000, he announced that the company would achieve a 25% improvement in fuel efficiency in the company's light truck fleet, including SUVs, by mid-decade. Under his direction, Ford Motor Company made technological progress toward improving fuel efficiency, with the introduction of the Hybrid Electric Escape, the most fuel-efficient SUV on the market, achieving 36 mpg (EPA) in city driving. The Escape's platform mates Mercury Mariner and Mazda Tribute were also scheduled to receive hybrid-electric powertrain options, along with other upcoming vehicles in the Ford product line including the Ford Fusion and Mercury Milan. Ford announced that half of the vehicle lineup would be available with advanced hybrid-electric powerplant options by 2010, although the Company's earlier pledge to build 250,000 hybrid vehicles a year by 2010 proved to be overly optimistic and had to be abandoned. Ford also continued to study Fuel Cell-powered electric powertrains and demonstrated hydrogen-fueled internal combustion engine technologies, as well as developing the next-generation hybrid-electric systems. In addition to the Ford Escape, Hybrid Escape, Mercury Mariner, and Mazda Tribute, Ford marketed high efficiency crossover SUVs such as the Ford Freestyle, the Volvo XC70 and the Volvo XC90. Ford also developed new crossover SUVs, such as the Ford Edge, Lincoln MKX, and Mazda CX-7. Ford expanded its lineup of flexible-fuel vehicles, alternative fuel vehicles, and dual-fuel vehicles. Flexible fuel vehicles can operate on a range of fuel mixtures – such as ethanol-gasoline blends ranging from pure gasoline to E85 (85% ethanol, 15% gasoline). Alternative fuel vehicles operate on non-petroleum fuels, such as methanol, compressed natural gas (CNG), propane, and hydrogen. Dual fuel vehicles generally have two fuel tanks – one for compressed natural gas or propane, and another for regular gasoline – with a selector switch to choose between them. Vehicles using those fueling alternatives were in test fleets, for example as taxis