As much as they employ similar management styles, Marchionne and Mulally differ in matters of strategy. Marchionne devotes a lot of time to issues around marketing and brands. He has tried to resuscitate such fading names as Alfa Romeo and Lancia and wants to reposition Chrysler's car lines. Mulally thought Ford needed to focus on the Ford brand alone, and sold Volvo, Jaguar, and Land Rover because they distracted from the effort.

    Marchionne believed that Fiat was too small to compete on a global scale so he arranged the linkup with Chrysler. Ford is twice the size of Fiat, so Mulally has moved more slowly forming alliances.

    Nor could their personal styles be more different. Marchionne presents himself like a '60s intellectual from a Fellini movie, with his baggy sweaters, longish hair, and cigarettes. He rations his public appearances and gets movie star treatment where shows up.

    Mulally, on the other hand, has the outgoing personality of a scout leader, and is invariably attired in a blue blazer, gray slacks, and red tie. His permanent expression seems to be a tooth smile.

    But the similarities of these two idiosyncratic leaders far outweigh the differences. Marchionne says his job is CEO is not to make business decisions -- it is to push managers to be leaders.

    In the end, Mulally's biggest job is to do the same thing: identify the one manager who can become the leader of Ford Motor after he leaves.

    If Marchionne can save Chrysler and grow Fiat, he could join Mulally in the top ranks of auto CEOs.