Soft compound difficulties for Mercedes

Mercedes have hailed their performance in the two winter tests, with James Allison saying the car has "a good turn of speed".

However driver Valtteri Bottas has revealed that the Silver Arrows are having problems with the softer compounds of tyres, especially with blistering.

The Finn told the media: "We have got the medium and hard tyres to work quite well I think.

"We still have issues with blistering on the softer compounds.

"Hopefully it will be different in Melbourne, but on the new track surface here in Barcelona we had some difficulties."

Pirelli has reacted ot these claims from Bottas, saying it is "not a suprise" that Mercedes were experiencing blistering, "considering the energy the cars are putting on the new tyres."

Pirelli's head of car racing Mario Isola also said regarding the Barcelona track: "It's high severity with a lot of high speed corners.

"The lateral forces in Turn 9, when they break at T.urn 1, they are full throttle until Turn 4. The speed is really high."

Despite this problem with the softer compounds, world champion Lewis Hamilton was upbeat, saying "It's been a really positive test. We got through everything, reliability has been great.

"It's still difficult to know exactly where we are in comparison to Red Bull and Ferrari and we won't fully know that until we get to the first race."

Despite this positivity, if Mercedes continue to have problems on the softer compounds, qualifying could be tough for them in Australia.