Maserati Quattroporte Sport GT-S Premieres in Detroit .fullpost{display:inline;} The sportiest to-date model of Maserati's Quattroporte range made its worldwide debut at NAIAS. The technical changes to the new Quattroporte Sport GT S compared to the 'S' model concern the mapping of the V8 4.7-litre engine which now produces 433HP, the new gearshift