Day of contrasts marks start of test season

Feb.2 (GMM) F1's 2015 test season kicked off on Sunday amid stark contrasts, as Mercedes looked set to extend its utter dominance into a second championship campaign.

The German giant, in fact, stunned rival engineers up and down the pitlane as Nico Rosberg pounded around the Jerez circuit almost 160 times -- a first-day feat perhaps unprecedented in the history of the sport.

Mercedes figures could even joke about it.

"Today we reveal our secret," smiled boss Toto Wolff, who is on crutches after a training accident.

"We want to do endurance racing at Le Mans as well," he joked, according to Germany's Auto Motor und Sport.

And world champion Lewis Hamilton, who spent the day in contract talks with Wolff and Niki Lauda, laughed: "Tomorrow we want to do 180 laps!"

In utter contrast, Force India is entirely absent at Jerez amid rumours of debt and supplier troubles, McLaren struggled to run at all amid more Honda teething trouble, while Lotus' new E23 only arrived at the circuit late on Sunday.

"It was expected that we would not run on the first day," Lotus driver Romain Grosjean told RMC Sport.

"I don't know if we will be ready on Monday but we will run on the last two days.

"We have pushed the development and parts arrived later than expected, but things are looking better than last year," the Frenchman added.

Sebastian Vettel, meanwhile, surprised the paddock by topping the times, although he conceded he might have been even happier had his new Ferrari been able to match Mercedes' stunning reliability feats.

"They (Mercedes) are very quick," said the German, "let's just hope not quite as fast as last year.

"Our aim this year must be to close the gap to them," he told reporters in southern Spain.

Italy's authoritative La Gazzetta dello Sport claims Ferrari may have been able to improve its engine by up to 80 horse power compared to last year, which if true will surely guarantee a much better season than 2014.

Vettel, meanwhile, pushed back against rumours he came close to quitting F1 last year as he struggled to thrive and enjoy the sport under the new V6 rules.

"You can either pack it in or accept it," he said. "I'm still here even if it's true I would prefer a big V12."

So for now, the paddock is expecting another year of Mercedes dominance, even if Rosberg and Hamilton are already playing down talk of more easy winning.

"Not long ago, Red Bull was unbeatable," said Rosberg. "They'll be strong again.

"Williams was just a few seconds behind Lewis at the last race in Abu Dhabi, and you always have to expect something from Ferrari and McLaren," the German added.

World champion Hamilton agreed: "We have taken a step, but to repeat what we did last year will be difficult.

"It's easier for those who are behind us to make bigger steps forward," the Briton mused.