Why the drivers will make the difference this year

On Monday I'm off to Barcelona for the test session. For many teams it is the final test before the season starts. For McLaren, Williams, Renault and Brawn GP there are another three days of running at Jerez from 15-17 March.

So it's a pretty vital week for a lot of teams, most of whom will bring heavly updated cars. It's a huge week for Ferrari, who have still not shown exactly where they are in the pecking order. Meanwhile McLaren have been having problems with the rear wing and although they have those extra days in Jerez, they will want to get on top of their problems as soon as possible this week.

Essentially the problem appears to be that McLaren's 2009 rear wing is stalling and causing rear end instability. They tried two difference versions in Jerez, but also stuck with the 2008 win for quite a bit of the time. They were never well up the time sheets and they did the lowest mileage of any team at Jerez.

This is a far from ideal state of affairs, but being McLaren they will get it sorted, I'm sure. It's quite a complex problem, but they have some amazing facilities and they will be running millions of calculations at the factory to find the answer.

Ferrari did not top the time sheets in Jerez last week and seemed to be focussed on working on set up and reliability. I hear from Italian colleagues that both drivers are now really happy with the balance of the car and with the way it works on the various compounds of Bridgestone's new slick tyre. They also seem pretty confident in their KERS system, which is a huge relief to them.

In Barcelona therefore, I expect them to bring many development parts and their job there will be to unlock more speed, because at the moment it seems that they do not have their noses in front. Part of the reason for that is the cool temperatures in Jerez last week. In the higher temperatures of Bahrain they were faster. The forecast is for clear weather n Barcelona, I'm delighted to say, so a lot of work will get done this week.

Renault are starting to look strong and all the signs are that BMW are doing the trick they did last winter of running with extra fuel to mask true performance. They trundle around and then every now and then do some electric laps, which indicates that the car has a lot of speed.

Toyota have been probably the most consistent team so far with good reliability, high mileage and good speed. Red Bull also looks pretty fast, Vettel did a very fast quali special in Jerez and this could be interesting in terms of the grid, as Webber is a sensational qualifier and I can see him sticking his car right up the front in Melbourne, Vettel too.

It looks like Force India are going to move up the grid as well. They have improved their chassis and the Mercedes/McLaren drivetrain and hydraulics package is a step forward. They've had some reliability problems and they were quite late out so they could be struggling to get the cars to the chequered flag in Melbourne, but I think they will be solid midfield runners this year.

So who's going to be at the back? Well team engineers I've spoken to are all surprised at how close the field is, the opposite of what everyone expected with such a massive rule change. They are starting to suggest that it will come down to drivers as to who's up and who's down. Yes, the field is that close, the drivers could well make the difference, especially with all the new responsibilities they have in the cockpit with adjustable front wings, KERS etc. If this is the case then it's brilliant news and I fear for the rookie Sebastien Buemi, for Nelson Piquet and possibly for Kazuki Nakajima, although, like Piquet he had some really good days mixed in with the bad ones last year.