Valtteri Bottas set the pace in F1 testing today
Mercedes, who have won 51 of the last 59 grands prix, are bidding to claim a quadruple of consecutive drivers' and constructors' championships this season.
And while Lewis Hamilton suggested Ferrari may be considered as the favourites heading into the forthcoming season, Bottas provided a glimpse of the potential from the sport's all-conquering team.
The Finnish driver's best effort of one minute and 19.310 seconds was faster than his quickest time of the opening test at the Circuit de Catalunya last week, and would have been good enough to seal pole position at the Spanish Grand Prix every year since the track layout was changed in 2007.
F1 2017 driver helmets: Every new design ahead of the upcoming season
Tue, February 28, 2017
Express Sport takes a look at every driver's new crash helmet ahead of the 2017 F1 season
1 of 21
Express Sport takes a look at every driver's new helmet ahead of the 2017 season
Bottas, who handed over the testing duties to team-mate Hamilton after the lunch break in Barcelona, also completed a decent haul of 70 laps. In total Mercedes managed 149 tours of the Spanish track – comfortably more than any other team – as they continued to rack up the all-important mileage ahead of the new season which gets under way in Melbourne later this month.
While Mercedes continued to show-off their impressive reliability there were problems for Red Bull and Ferrari, too, while McLaren's troubled pre-season does not appear to be turning a corner.
Following another engine failure which curtailed Stoffel Vandoorne's running on Tuesday, Fernando Alonso managed the fewest laps (46) of any of the drivers who had a complete day behind the wheel.
Get Quotes on Home Insurance
Valtteri Bottas replaced Nico Rosberg at Mercedes in the off-season
The British team insisted there were no concerns with their so-far unreliable Honda engine, but their lack of mileage and slow pace – Alonso was nearly four seconds slower than Bottas – will do little to ease the tension at the British team with just two full days of testing left.
Red Bull were forced into an unscheduled engine change at lunch before Max Verstappen broke down in the final hour of the day.
Over at Ferrari, Kimi Raikkonen lost control of his car at turn three and was left stranded in the gravel. The Finn crashed into the barriers and sustained damage to his car, forcing a premature end to his day.
Lance Stroll, the 18-year-old Canadian rookie who spun three times last week, will have been pleased to get an error-free run under his belt. His Williams team-mate Felipe Massa was second in the order, just behind Bottas, with Raikkonen a full second further back in third. Hamilton, who focused on long stints rather than overall lap time, was sixth fastest.
British driver Jolyon Palmer completed only 29 laps for Renault in the afternoon and was slowest of all the runners.