premise: Sebastian Vettel was not a race car driver.
hypothesis: Sebastian Vettel ( [ zeˈbasti̯an ˈfɛtl̩ ] ; born 3 July 1987 ) is a German racing driver currently driving in Formula One for Scuderia Ferrari . Since he is one of only four drivers to have won four or more drivers ' titles , he is among the most successful F1 drivers of all time . Vettel started his career in Formula One as a test driver for BMW Sauber and made his debut with the team at the 2007 United States Grand Prix , replacing the injured Robert Kubica . In his first year driving for Red Bull in , Vettel finished the season as the youngest-ever World Drivers ' Championship runner-up . The following year he went on to become the youngest driver ever to win the World Drivers ' Championship , aged 23 .