Friday in Barcelona: Vettel is fast, wary and warned

A mixture of sunshine and clouds greeted the drivers during running today at the Circuit de Cataluyna as both 90 minute sessions were run in dry conditions. A 1-2 for McLaren in the first session was followed by Red Bull domination in the second session with Sebastian Vettel on top of the timesheets.

Red Bull and McLaren seem to be the two teams most likely to be battling for the front row tomorrow. Behind them was the most fascinating points of the day as Mercedes raft of changes seem to bring benefit to Michael Schumacher who was 3rd in both sessions and Ferrari, who spent a lot of time concentrating on evaluating their cars running with and without the F-Duct system. Of course, for Mercedes and Schumacher the acid test of their pace will come tomorrow but certainly Schumacher seemed more at ease with the car and that should breed both confidence and speed. Ferrari seem reasonably happy with their F-Duct and looks set to use it for the whole weekend. The car looked a bit loose at times and they will want to nail the balance of the car before the start of qualifying tomorrow.

It was a bad day for Nico Hulkenberg who dropped the car on the exit of turn 9, heading across the track and into the barrier. This caused a delay though for Williams it is only Rubens Barichello with an updated car this weekend. Jaime Alguersuari stopped near the end of the second session. Sauber had gearbox problems with Pedro De La Rosa but they were pleased with the progress they had made with their F-Duct. They have Burger King as a new sponsor. Jarno Trulli was delighted with the improvements Lotus had made and said there was more to come. Christian Klien got his superlicense 10 minutes before first practice and drove Karun Chandok's car, lapping half a second faster than Bruno Senna. Virgin had their new car in the hands of Timo Glock and despite his slow pace, Nick Wirth is confident that there is much more to come from the new chassis.

There were other stories doing the rounds today. These included Pirelli making an offer to be sole tyre supplier from 2011. Michelin and Avon have also expressed an interest with the French manufacturer seemingly favourite to take over the role though it prefers being joined by another company in suppling tyres. There hasn't been a tyre war in F1 since 2006. The teams have been told that any one off changes to the qualifying format for Monaco can only be made with the agreement of them all. There are fears that traffic could be a major problem in the principality next weekend. Apparently Charlie Whiting made it clear in Fridays drivers briefing that he was unimpressed with Sebastian Vettel's squeezing of Lewis Hamilton in the pitlane in Shanghai and that anyone repeating it would face more than a reprimand. He said that cars side by side in the pitlane would be fine providing the track was wide enough and both drivers gave space to each other

Tomorrow could well be the crunch day with grid position being so particularly important in Barcelona. Rain is forecast overnight, hence washing the track clean and though Practice tomorrow may be in damp conditions, it should be a dry qualifying session which Red Bull will enter as strong favourites although Vettel remains wary of McLaren's true pace. The current weather situation for Sunday is for rain to arrive at 4pm local time which would be after the race. Its been 14 years since a wet Spanish Grand Prix. For UK readers, the BBC's coverage will be only on BBCi and online for the first 30 minutes before BBC1 starts its coverage 15 minutes before the start of the qualifying session. Follow the blog and my Twitter for updates throughout the weekend