Mercedes may have topped both practice sessions on Friday based on their outright pace, but chief rival Ferrari were ahead in long runs.
Valtteri Bottas headed a Mercedes 1-2 in FP2, with the nearest Ferrari of Kimi Raikkonen finishing three tenths adrift in third.
However, Raikkonen’s long run on supersoft tyre would be a cause of worry for the Brackley and Brixworth-based squad.
On a 15 lap stint where 11 laps were representative, Raikkonen set an average time of 1m32.963s with limited degradation.Lewis Hamilton’s stint was of the exact same length but his performance tailed off towards the end, leaving him with an average of 1m33.116s.
Bottas was marginally quicker than Raikkonen by a tenth, but his stint was of nearly half the length. The Finn’s pace made it further clear that Mercedes is likely to face some tyre woes on Sunday.
Another team to suffer from high degradation was Red Bull with Daniel Ricciardo recording a severe drop off in his laptimes. After starting in high 1m33s, he was lapping firmly in 1m34s - ending with an average time of 1m34.208s after 11 laps.
Max Verstappen had a better outing than his teammate, but he was still no match to Mercedes or Ferrari. Friday’s pace will prove to be a setback to Red Bull who had brought an incremental update at this race ahead of a major upgrade planned for Hungary.
Interestingly, Mercedes decided not to do any long runs on soft tyres, with Bottas instead preferring to do a race simulation on the white-striped medium compound.
On soft rubber, Vettel held the edge over teammate Raikkonen, with the Red Bull drivers further behind despite doing fewer laps on those tyres.
Importantly, Vettel’s soft tyre run was partially quicker than Bottas’ on the medium tyre, although the better durability of the latter may swing the advantage to the Mercedes driver’s favour come race day.
Supersoft 1:32.833 (8 lap stint, 6 counted)
Kimi Raikkonen 1:32.963 (15 lap stint, 11 counted)
Lewis Hamilton 1:33.116 (15 lap stint, 11 counted)
Sebastian Vettel 1:33.414 (10 lap stint, 7 counted)
Max Verstappen (1:33.806 12 laps, 8 counted)
Daniel Ricciardo- 1:34.208 (11 lap stint, 9 counted)
Sebastian Vettel Soft 1:32.877 (13 lap stint, 10 counted)
Kimi Raikkonen 1:33.302 (9 lap stint, 7 counted)
Verstappen 1:33.471 (12 lap stint, 6 counted)
Daniel Ricciardo 1:33.776 (12 lap stint, 6 counted)
Valtteri Bottas 1:33.958 (10 lap stint 8 counted_
by Rachit Thukral