Barcelona F1 test round-up: Lotus fastest but Mercedes stars

Grosjean used Pirelli's super-soft tyres on Sunday to make it three out of four days on top for the team, after team-mate Pastor Maldonado went quickest on Thursday and Saturday in the new E23.

Despite Lotus's new-found pace with its latest car and switch from Renault to Mercedes power, and Daniel Ricciardo topping day two for Red Bull, it was last year's dominant force that made the biggest impression at Barcelona.

Nico Rosberg did not use either of the two softer-compound Pirellis on Sunday, but with medium rubber on the W06 the 2014 runner-up set the second fastest time of the week, just a quarter of a second behind Grosjean's best on tyres that are 1.5s-2s faster.

That followed an ominous race simulation from world champion Lewis Hamilton on Friday, during which he was comfortably faster than Ricciardo's Red Bull, despite again being on slower rubber and running longer on his stint.

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Such a positive result for Mercedes looked in doubt after Thursday, when reserve driver Pascal Wehrlein had to be recalled from Force India in the afternoon duo to Hamilton falling ill with a fever and a neck issue stopping Rosberg from taking over.

Despite the setback the W06 completed more mileage than any other car at the test, racking up 446 laps (or 1290 miles).

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The Renault-powered Red Bull and Toro Rosso were next-best on the mileage count, both within 50 laps of Mercedes' tally, and Ricciardo topped Friday with the best soft-tyred time of the week.

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The Aussie narrowly outpaced Kimi Raikkonen's Ferrari and Felipe Massa's Williams on day two, and he was 0.4s faster than team-mate Daniil Kvyat managed on Sunday.

It was a much-improved turnover of laps for the four-time champion team, but the same could not be said for McLaren-Honda, which had a dismal test that was constantly thwarted by MGU-K seal issues.

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Fernando Alonso and Jenson Button completed just 124 laps between them with almost half of that tally achieved on Saturday.

Both drivers were unable to string a significant number of laps together, and Button managed just 45 in total.

A disastrous week was compounded when Alonso suffered concussion in a crash on the final morning that required an overnight hospital stay and stopped Button taking over in the afternoon as planned.

With Mercedes not using the softer tyres and Williams opting to keep clear of performance runs as well, save for Massa's soft-tyre effort on Friday, laptimes were not a clear indicator of the pecking order.

Raikkonen gave further encouragement that Ferrari's SF15-T will move it closer to the front of the grid by shadowing Ricciardo on Friday, 0.010s behind.

But the Scuderia lost time on Sunday with what Sebastian Vettel called "teething problems".

Elsewhere, Force India's Sergio Perez and Toro Rosso's Max Verstappen used super-soft tyres to set the seventh and eighth best times of the week, but both teams were compromised on the final day.

Nico Hulkenberg's Force India detonated its Mercedes engine, while Carlos Sainz Jr crashed at Turn 3 in the Toro Rosso.

Combined laptimes:

Pos  Driver            Car                   Time       Gap     Day  Tyres
 1.  Romain Grosjean   Lotus-Mercedes        1m24.067s           4   SS
 2.  Nico Rosberg      Mercedes              1m24.321s  +0.254s  4   M
 3.  Pastor Maldonado  Lotus-Mercedes        1m24.348s  +0.281s  3   SS
 4.  Daniel Ricciardo  Red Bull-Renault      1m24.574s  +0.507s  2   S
 5.  Kimi Raikkonen    Ferrari               1m24.584s  +0.517s  2   S
 6.  Felipe Massa      Williams-Mercedes     1m24.672s  +0.605s  2   S
 7.  Sergio Perez      Force India-Mercedes  1m24.702s  +0.635s  2   SS
 8.  Max Verstappen    Toro Rosso-Renault    1m24.739s  +0.672s  3   SS
 9.  Lewis Hamilton    Mercedes              1m24.923s  +0.856s  2   M
10.  Daniil Kvyat      Red Bull-Renault      1m24.941s  +0.874s  4   S
11.  Felipe Nasr       Sauber-Ferrari        1m24.956s  +0.889s  4   SS
12.  Valtteri Bottas   Williams-Mercedes     1m25.345s  +1.278s  4   S
13.  Carlos Sainz Jr   Toro Rosso-Renault    1m25.604s  +1.537s  4   SS
14.  Fernando Alonso   McLaren-Honda         1m25.961s  +1.894s  2   S
15.  Jolyon Palmer     Lotus-Mercedes        1m26.280s  +2.213s  2   S
16.  Sebastian Vettel  Ferrari               1m26.312s  +2.245s  4   S
17.  Marcus Ericsson   Sauber-Ferrari        1m26.340s  +2.273s  3   S
18.  Nico Hulkenberg   Force India-Mercedes  1m26.591s  +2.524s  4   S
19.  Pascal Wehrlein   Force India-Mercedes  1m27.333s  +3.266s  3   M
20.  Jenson Button     McLaren-Honda         1m28.182s  +4.115s  1   M
21.  Pascal Wehrlein   Mercedes              1m28.489s  +4.422s  1   H
22.  Susie Wolff       Williams-Mercedes     1m28.906s  +4.839s  1   M

Mileage by driver:

Pos  Driver            Laps  Miles
 1.  Max Verstappen    223   645
 2.  Daniil Kvyat      216   625
 3.  Daniel Ricciardo  202   584
 4.  Lewis Hamilton    201   581
 5.  Nico Rosberg      197   570
 6.  Carlos Sainz Jr   188   544
 7.  Sebastian Vettel  181   523
 8.  Valtteri Bottas   178   515
 9.  Pastor Maldonado  173   500
10.  Marcus Ericsson   166   480
11.  Kimi Raikkonen    164   474
12.  Pascal Wehrlein   161   466
13.  Sergio Perez      155   448
14.  Felipe Nasr       152   440
15.  Felipe Massa      143   414
16.  Romain Grosjean   111   321
17.  Susie Wolff       86    249
18.  Fernando Alonso   79    228
19.  Jolyon Palmer     77    223
20.  Jenson Button     45    130
21.  Nico Hulkenberg   36    104

Mileage by team:

Pos  Team         Laps  Miles
 1.  Mercedes     446   1290
 2.  Red Bull     418   1209
 3.  Toro Rosso   411   1189
 4.  Williams     407   1177
 5.  Lotus        361   1044
 6.  Ferrari      345   998
 7.  Sauber       318   920
 8.  Force India  304   879
 9.  McLaren      124   359

Mileage by engine:

Pos  Engine    Laps  Miles
 1.  Mercedes  1518  4390
 2.  Renault   829   2397
 3.  Ferrari   663   1917
 4.  Honda     124   359