Nico Rosberg denied Lewis Hamilton a clean sweep in practice ahead of the Spanish Grand Prix, although it was another Mercedes one-two.
The final hour-long session ahead of qualifying, however, was more about assessing different options than going for outright pace.
Rosberg topped the timesheet at Barcelona's Circuit de Catalunya with a lap of one minute 25.887secs, a third of a second slower than Hamilton's best lap from Friday's two 90-minute outings.
Hamilton himself finished 0.869secs down on Rosberg, and 1.2secs off the pace of his fastest of yesterday, underlining Mercedes' target of looking more at long-run, high-fuel simulations.
It was a similar story for their rivals, although the gap was again considerable, with Ferrari's Fernando Alonso third on the board, but 1.301secs behind Rosberg.
Williams' Felipe Massa was just a few hundredths of a second behind former Ferrari team-mate Alonso in fourth, followed by the Lotus of Romain Grosjean, but with the Frenchman 1.8secs back.
Spanish Grand Prix - In pictures
Spanish Grand Prix - In pictures
1/10 Sunday race
Lewis Hamilton celebrates with his trophy after winning the Spanish Grand Prix
Nico Rosberg attempts to hunt down his Mercedes team-mate in the battle for Spanish Grand Prix glory
3/10 Saturday final practice
Spanish hero Fernando Alonso prepares to head out where he will receive the usual ferocious support he has grown used to in Barcelona
4/10 Saturday final practice
Nico Rosberg finished fastest in final practice for the Spanish Grand Prix ahead of Lewis Hamilton
5/10 Saturday final practice
Williams' Felipe Massa walks through the pit-lane ahead of qualifying
6/10 Friday second practice
Esteban Gutierrez negotiates the sweeping turns 1 and 2 in his Sauber
7/10 Friday second practice
Daniel Ricciardo enjoyed a far more successful practice session as he ran behind the Mercedes pair in third position
8/10 Friday first practice
A concerned Sebastian Vettel keeps guard over his broken down Red Bull as he looks on with a fire extinguisher at the ready
9/10 Friday first practice
Sebastian Vettel pushes his Red Bull after it grinds to a halt on the Catalunya track
10/10 Friday first practice
Lewis Hamilton leads the first practice at the Spanish Grand Prix
McLaren duo Kevin Magnussen and Jenson Button were sixth and eighth, sandwiching Red Bull's Daniel Ricciardo, a full two seconds adrift.
Sebastian Vettel, who missed most of Friday due to a wiring loom fault with his Red Bull, completed a session-high 20 laps as he attempted to make up for lost time.
The reigning four-times champion had to settle for the 10th fastest time, 2.2secs adrift of Rosberg, but with obviously far more remaining in the locker.
Down in 14th was Kimi Raikkonen in his Ferrari, 2.6secs adrift, with Max Chilton 19th, but only after ending his morning with another run into the gravel.
Chilton finished the second session by kicking up a pile of stones, and he did the same in FP3, although at least finished ahead of team-mate Jules Bianchi and Caterham duo Kamui Kobayashi and Marcus Ericsson.
Final Positions after Third Practice:
1 Nico Rosberg (Ger) Mercedes 1min 25.887secs
2 Lewis Hamilton (Gbr) Mercedes 1:26.756
3 Fernando Alonso (Spa) Ferrari 1:27.188
4 Felipe Massa (Bra) Williams 1:27.223
5 Romain Grosjean (Fra) Lotus 1:27.682
6 Kevin Magnussen (Den) McLaren 1:27.806
7 Daniel Ricciardo (Aus) Red Bull 1:27.808
8 Jenson Button (Gbr) McLaren 1:28.006
9 Pastor Maldonado (Ven) Lotus 1:28.076
10 Sebastian Vettel (Ger) Red Bull 1:28.085
11 Valtteri Bottas (Fin) Williams 1:28.101
12 Jean-Eric Vergne (Fra) Toro Rosso 1:28.242
13 Daniil Kvyat (Rus) Toro Rosso 1:28.298
14 Kimi Raikkonen (Fin) Ferrari 1:28.419
15 Sergio Perez (Mex) Force India 1:28.571
16 Nico Hulkenberg (Ger) Force India 1:28.668
17 Adrian Sutil (Ger) Sauber 1:28.715
18 Esteban Gutierrez (Mex) Sauber 1:28.865
19 Max Chilton (Gbr) Marussia 1:30.169
20 Jules Bianchi (Fra) Marussia 1:30.670
21 Kamui Kobayashi (Jpn) Caterham 1:30.712
22 Marcus Ericsson (Swe) Caterham 1:31.559