Will 'elimination qualifying' disrupt Mercedes' dominance? Will it produce more surprises in qualifying - or stop them? F1's newest rules tweak analysed.
As teams prepare for the second and final pre-season test next week, look back on this week's running with this gallery of new pictures.
In the round-up: FIA to end 'designed to degrade' tyres • Qualifying plan "a waste of time" - Hamilton • Sainz warns over weight
Lewis Hamilton said Mercedes had begun the season with "the best test we've ever had" after the team overwhelmingly topped the mileage charts.
Toro Rosso technical director James Key says the team has been pleasantly surprised by how much ground they've covered with the STR11.