Mar.5 (GMM/ Lewis Hamilton has admitted his ongoing concerns about Pirelli’s F1 tyres.

In 2013, drivers were bemoaning the quality and high degradation of the Italian supplier’s product, but last year Pirelli was accused of being too conservative.

In pre-season testing, however, the cars of 2015 have proved significantly quicker than last year.

“We’ve seen a difference of up to two seconds,” said Pirelli chief Paul Hembery, “and that gap could be even bigger on the softer compounds.”

For 2015, Pirelli has tweaked the construction of the rear tyres, and a brand new ‘super soft’ compound has been introduced.

However, F1’s official supplier will not take the super-soft to Australia; a move described by insiders as conservative.

Reigning world champion Lewis Hamilton admitted recently that he remains unimpressed with Pirelli’s 2015 range.

“The biggest issue is the tyres,” he told the French broadcaster Canal Plus during recent Barcelona testing.

“They just don’t work, they’re so hard. They’re not spectacular.”

But Hembery suggests that the new Pirellis should not be judged until the season starts, when temperatures will be higher than in testing.

“(Testing) conditions were still generally much cooler than we will typically see at most of the races, so this is a factor that has to be considered,” he said.