Mercedes explain lack of headline testing pace

Mercedes chief Toto Wolff has explained the Silver Arrows' lack of headline-grabbing lap times at the pre-season test. While title rivals Ferrari topped the timesheets in Barcelona, Wolff says his team opted agains using the fastest hypersoft tyre, as he does not expect them to be useful in races next year.

Sebastian Vettel and Kimi Raikkonen each stopped the clock in the low 1min 17s, times never before seen at the Circuit de Catalunya in its current layout.

Daniel Ricciardo and Fernando Alonso also delivered impressive one-lap pace late in the fortnight.

However, neither Lewis Hamilton or Valtteri Bottas made the top five, both focusing largely on long-run simulations and putting most laps into the medium tyre.

Wolff explained that they hypersoft compound's lack of lifespan was the reason for Mercedes' approach.

"We decided not to use the hypersoft because we felt it is a tyre that is usable for one lap only, and that in testing it is about collecting data and understanding set-ups," he said.

"The hypersoft is just an additional big step in grip from the ultrasoft. It will be a qualifying tyre, and we felt that we would rather concentrate on the development work than on single lap."

Wolff's assessment of the hypersofts means we could be in for intriguing starts to races this year.

The top 10 qualifiers must start races on the tyres they set their best time with, and Wolff suggested the leaders could be in "survival" mode off the line this year.

"I think the hyper will be a qualifying tyre only, and you just need to hang onto it in the first couple of laps, and survive."

Pirelli have suggested that they expect each tyre to be worth over half a second in lap time as the compounds get softer and softer, but Wolff says there is little evidence to back this up so far.

"What we have seen is that the steps in performance and in grip between the tyre compounds was relatively small," he said.

"Between medium and soft, soft and supersoft, supersoft and ultrasoft you could see tiny steps, between a tenth or two, sometimes no step at all.

"With some teams, like Williams, there was no step at all."