|By Andrew Benson, Chief F1 writer at the Circuit de Catalunya|
|Spanish Grand Prix|
|Venue: Circuit de Barcelona-Catalunya Dates: 8-10 May|
|Full BBC coverage details|
Lewis Hamilton was in a league of his own as the Mercedes driver set the fastest time in second practice at the Spanish Grand Prix.
The world champion was 0.408 seconds up on Ferrari's Sebastian Vettel, with Mercedes team-mate Nico Rosberg third.
Rosberg was a substantial 0.764secs off Hamilton's pace and 0.164secs ahead of Ferrari's Kimi Raikkonen.
Red Bull's Daniil Kvyat was fifth ahead of Toro Rosso's Max Verstappen and the improved McLaren of Jenson Button.
The Englishman was 0.229secs and four places ahead of team-mate Fernando Alonso, who made an error in the final sector of his fastest lap and ended up 11th.
Their positions hinted that the improved performance McLaren promised may be delivered this weekend.
McLaren and engine partner Honda have brought upgrades to both car and engine this weekend and were expecting a step forward in performance, as they have made at every race since a very disappointing start to the season.
If they were able to repeat those positions and qualify in the top 10 on Saturday afternoon it would be a dramatic advance, although they are likely to be overtaken by other teams who can turn up their engine performance for qualifying.
Among them will be Williams, whose driver Valtteri Bottas was edged out by 0.031secs by Button as Toro Rosso's Carlos Sainz took eighth ahead of Bottas's team-mate Felipe Massa.
Mercedes look to have a significant edge on single-lap pace and are again strong favourites for qualifying but Ferrari appear as usual much closer on race pace.
The relative positions of the Mercedes drivers swapped on the race-simulation runs late in the session. Rosberg had a slight advantage but only small - about 0.07secs on average lap time.
Vettel was a second slower on average lap time than the Mercedes drivers over his race run and afterwards admitted that the gap between the two teams was "still there".
"It's been OK," said Hamilton. "A fairly decent day. It is quite windy so the car is affected by that but otherwise it's been quite good. Our pace feels good."
Raikkonen did run the medium tyre at the same time as the Mercedes, albeit briefly, and appeared to lack the world champions' pace.
Red Bull hit more reliability trouble with the Renault engine, Daniel Ricciardo needing a power-unit change and only getting out for the final five minutes of the session, setting the 13th fastest time behind the Lotus cars of Romain Grosjean and Pastor Maldonado.
|Andrew Benson's view of the Spanish GP|
|The Spanish Grand Prix at the Circuit de Barcelona-Catalunya has taken the place that used to be held by the much-loved San Marino race at Imola - a comfortable and familiar-feeling start to the European part of the Formula 1 season.The track is nestled in the Valles region north of Barcelona, an incongruous mix of verdant hills and heavy industry, and it lacks the atmosphere and buzz of Imola.But it is lent a charm of its own by the warm Spanish sunshine, drifting, filigree spring seeds, hazy Pyrenean backdrop and proximity of one of the world's great cities.The track tends not to produce brilliant racing - overtaking is exceptionally difficult because of the plethora of corners.But those bends - all long-duration, mostly medium-speed and some exceptionally fast, particularly the challenging Turn Three - provide one of the sternest all-round tests for a grand prix car's capabilities on the calendar.|