The Spanish Grand Prix preview

Modern Formula 1 is all about aerodynamics. And no track is more aero-dependent than Barcelona's Circuit de Catalunya. No surprise that only three times in 20 years has the team winning there failed to clinch the Constructors' Championship.

That's bad news for Red Bull's rivals. Barcelona is an Adrian Newey playground. Last year, at the fast Campsa corner, Mark Webber and Sebastian Vettel were able to hurtle through at full throttle in sixth gear in qualifying - a gear higher than the team's rivals. Unless Ferrari or McLaren have made a giant leap forward, which is almost inconceivable, only a disaster for the team will prevent a fourth Red Bull win in five races.

The question is, which driver? Vettel is clearly the favourite having lead over 80 per cent of this year's racing laps and taken all four pole positions. With a 38-point lead over Lewis Hamilton, it's way too early to declare him champion-elect, but history tells us that a runaway leader early in the season is very often still there come the end.

In Barcelona, it's surely Webber's chance to stake a claim for the title. He won here last year, leading every single lap from pole position, backing it up with another triumph a week later in Monaco.

He has started the season disappointingly and struggled to master the new Pirelli tyres as quick as his team-mate, but has shown the raw speed to get on terms with him, if only in flashes. This weekend should be the ideal opportunity to remind everyone why he came so close to the title last year, even though holding a candle to Vettel on current form might be impossible.

As for the battle for best of the rest, it's hard to call between McLaren, Ferrari and Mercedes. All three will fancy their chances of being first in the queue to pick up the pieces if Red Bull hits trouble.

McLaren struggled in Turkey and it's hard to see Hamilton finishing any higher than fourth even without the problems he endured in the race. A major upgrade package will be tried on Thursday, which the team hopes will allow it to reassert itself as Red Bull's nearest challenger.

For Ferrari, the season can only get better. This weekend, it will have the first upgrades signed off since it troubleshooted its wind tunnel correlation problems. There is plenty of potential downforce to be unlocked in the car and if it can get its airflow regime working as it intends, then Fernando Alonso might be able to consider qualifying somewhere other than fifth for the first time this year.

As for Mercedes, it too has upgrades and went very well during the final pre-season test at Barcelona. Finding the balance between qualifying and race pace is the key, with the balance tipped too far towards Saturday afternoon in Turkey, but Nico Rosberg in particular has proved himself to be a serious threat for the top half-dozen.

As for Michael Schumacher, he has shown real pace in flashes. Last year, he had a strong weekend in Barcelona and could surprise those clamouring to write him off.

The unknown quantity heading to Barcelona is Renault. After two podiums in the opening two races, the team looked on an upward curve, but in Turkey Nick Heidfeld and Vitaly Petrov were worryingly close to being pulled deep into the midfield.

Hopefully Barcelona, a track that traditionally gives us the clearest picture of the overall performance ranking of the cars, will show exactly where the Enstone team really is in the pecking order.

Weather

Strategy

Tyres will once again be key, and, as in Turkey, Pirelli has allocated its soft and hard compounds. How many stops will be required will be determined largely by how well the drivers can hang on to their rubber through the succession of long corners at Barcelona.

Of all the corners, it is the third turn that will have the biggest effect on tyres. The fronts will be eaten alive by an understeering car while oversteer will make life hell for a driver, and will have huge knock-on effect in terms of rubber life in the acceleration zones out of SEAT, La Caixa and the chicane.

A three, or even four stop strategy - as was employed by a few teams in Turkey - is therefore likely.