Barcelona Testing – Haas and Williams have added T-wings onto their cars ahead of pre-season testing.
Both teams had a shark fin on their launch-spec cars, but have added the new T-wing on top of the existing bodywork.
The shark fin is returning to the majority of car designs as the aerodynamic regulations have opened for 2017 season as Formula One seeks more aggressive-looking cars.
Mercedes were the first to display the T-wing during their shakedown session at Silverstone on Thursday. They are the only team to have steered away from the shark fin rear bodywork.
Mercedes are trialling a combined T-wing and shark fin in the afternoon session of Monday’s running with Lewis Hamilton.
Ferrari had the combined design at the unveiling of their car and shakedown at Fiorano.
The T-wing’s purpose is believed to be improving airflow to and around the rear wing, rather than actually improving downforce levels.
Red Bull, McLaren, Renault, Force India, Toro Rosso and Sauber have only run with the shark fin designs seen at their respective launches.
McLaren and Toro Rosso, however, are expected to experiment with the T-wing during testing.