Red Bull and McLaren have the quickest cars as formula one teams prepare for the final pre-season test before Melbourne.

That is the view of Sauber designer Matt Morris, despite the Swiss team's Kamui Kobayashi setting the fastest overall time at last week's Barcelona test.

"The top teams are yet to show their hands," read a report in the German magazine Auto Motor und Sport.

Morris agrees with that assessment.

"If we are to believe our own analysis then Red Bull and McLaren are in front, there is a question mark about Ferrari, and behind them is a very close group of several teams.

"I think the gaps between those in this central group will be smaller this year," he added.

The F1 world's real gaze this week will however be on the apparent title contenders, with Lewis Hamilton quoted by the SID news agency as saying: "Maybe Red Bull are a bit quicker than us."

But McLaren's team boss Martin Whitmarsh revealed: "We will have a fairly substantial (update) package in Barcelona this week.

"We assume Red Bull will do the same," he added.

Unlike last year, however, there will be no last-minute technical sensation that determines the pecking-order for the start of the season.

Sauber's Morris explains: "There will be nothing spectacular; the rules don't allow it any more."

But he admitted that the best-funded teams will continue to tinker at the edges, as demonstrated by McLaren, Ferrari and Red Bull who have so far run several different exhaust configurations in the wake of the blown diffuser ban.

Morris said: "Any modification in this area is an expensive pleasure, while before we (Sauber) do anything, we have to be sure that it is clearly better."