Jenson Button believes this year’s Formula One cars could be almost as slow as those in GP2 in the early stages of the season.

The true pace of the 2014 models was far from unleashed in the first pre-season test in Jerez last week as the teams attempted to get to grips with the new technology at their disposal.

Button’s new McLaren teammate Kevin Magnussen produced the fastest lap over the four days of one minute 23.276secs, 5.4secs slower than the best on the Spanish track a year previously.

Although the situation will improve as the season progresses, in comparison to the cars in GP2, which is F1’s support series, Button said: “They’ll be a lot closer on certain circuits.

“We’ll be quicker, but not that much quicker. Then again it was the first test with a very new package.”

Explaining that two-second loss of pace, Button added: “This year’s tyres, we think, are half a second slower.

“The cars are also heavier, about one to 1.2 seconds through weight, so that’s 1.6, 1.8 seconds already from those two changes.”