Brazilian F1 Grand Prix: Mercedes-AMG’s Valtteri Bottas Quickest During Friday Practice

His best lap of 1:08.846 came in FP2, and surpassed that of his teammate Lewis Hamilton by three thousandths of a second. Meanwhile, Hamilton this debuted a new helmet to commemorate his fifth world title, won in Mexico, with five stars meant to represent each of his championships.

Both Mercedes drivers led by a narrow margin over their counterparts at rival teams Scuderia Ferrari and Red Bull Racing, where the prancing horse sandwiches the bulls. Almost a half second separates Sebastian Vettel and Kimi Räikkönen, both Red Bull drivers leaning closer to Vettel's time than Räikkönen's.

Vettel's focus during practice may have suffered due to a loose item in his cockpit, about which he quipped comically over the radio.

Behind the frontrunners, a rebounding Romain Grosjean leads the midfield, placing his Haas VF-18 just under four tenths behind the trailing Ferrari. Nearest him is Charles Leclerc, almost two tenths behind. Grosjean's teammate Kevin Magnussen keeps Leclerc company, as does Force India's Esteban Ocon, both around two tenths off from the Monegasque driver's best times.

The regular upper-midfielders at Renault struggled to place their cars in the top ten in practice, Carlos Sainz Jr. managing only P14, his teammate Nico Hülkenberg failing to improve in FP2 due to a crash early on that red-flagged the session. As a result, even Fernando Alonso of McLaren laid down better times than either Renault driver, despite his McLaren MCL33 going almost undeveloped since the Spanish Grand Prix in May.

Three test or reserve drivers appeared in FP1, two in place of drivers who will be replaced at their respective teams in 2019.

A full list of each driver's best times and margin of improvement between sessions can be found below.