Welcome back to Shanghai ahead of qualifying for the Chinese Grand Prix. No prizes for guessing who was fastest in free practice and Sebastian Vettel is undoubtedly the favourite to take pole position in the upcoming qualifying hour. But the McLarens are close and the Red Bull, albeit on Mark Webber's side of the garage, is showing signs of weakness with an electrical problem in FP3.

The engines are being fired up with just a few minutes left before Q1 when seven drivers will be knocked out and form the back seven places on the grid.

Here's Ferrari's prediction: "It will be a tough Q session. Apart from Red Bull and McLaren, who are out of reach, Mercedes looks very strong."

Mechanics have been surrounding Webber's car since FP3 but the engine covers are now going back on with shouts of "wahey" from the team. We'll keep an eye on the TV feed to see if his KERS is back up and running for this session.

Meanwhile all is calm in the McLaren garage as Hamilton tries to get in the zone for this crucial session. In Malaysia he destroyed a set of soft tyres during qualifying and that compromised him in the race, so he'll be determined to avoid a repeat this time out.

Perez hits the track in the Sauber and gets the session underway.

Perez is on hard tyres but I suspect he will have to crack in to a set of softs to get through this session.

Ferrari says: "Weather has not changed since FP3 with cool temperatures and wind."

So that's a track temperature of 26C and an air temperature of 15C. The wind speed is 6.3mps if that means anything to you, if it doesn't just read breezy.

Heidfeld attempts a lap on softs but it's a second off Perez who set a 1:37.585 on his third lap on hard tyres.

Latest from Red Bull is that it is very ulikely Webber will be using KERS. Very bad news for him, not so much today but certainly for the start tomorrow.

Steven's opinion on the gap between Webber and Vettel is: "It's obvious to see with RB as to who gets the preferential treatment with the better car setup? It's all BS how one can be so on top of the time sheet when they say there's equal treatment between each driver. My heart goes out to Webber with all that he is going through."

Quite a few people writing in agree with Steven.

Alguersuari's car seems to be magnetically drawn to the artificial grass on the exit of the final turn. Despite leaning on it heavily, he still goes second fastest on soft tyres with a 1:36.133.

Vettel goes fastest with a 1:35.891 on hard tyres. He's just under a tenth quicker than Button. Webber meanwhile can only manage seventh fastest.

Vettel improves by a couple of tenths to a 1:35.674. The objective for the top teams in this session is to get through without using soft tyres. I suspect the top three will manage that with their current times quite easily.

Kobayahsi is using a set of softs as he attempts his first fling lap.

On a seperate note, the two HRTs are comfortably within 107% of the fastest time so far. And Liuzzi is just 0.4 seconds off Glock's Virgin.

Heidfeld is out on soft tyres, he obviously feels a little bit under pressure after missing out on set-up time on Friday with a couple of spins. But he needn't worry now as he's gone second fastest.

Di Resta gets himself out of trouble near the drop zone with the second fastest lap. He's less than a tenth off Vettel, albeit on soft tyres.

The Ferraris are going back out on softs, they aren't happy with their pace.

Petrov is currently in the drop zone, but we know from Heidfeld's time that the car is quick enough on softs.

Alonso goes fastest of all but has now used a set of soft tyres.

Massa goes second fastest but that's not what it seems as Red Bull and McLaren have not set a quick lap yet on soft tyres.

Schumacher, Maldonado and Webber are all near the drop zone and Webber is still attempting to set a lap on hard tyres.

Webber under pressure as Schumacher and Maldonado are on quick laps.

Webber is out in Q1! Maldonado and Schumacher set better times on soft tyres, leaving Webber - without KERS - starting from 18th tomorrow.

Huge tactical error not to use soft tyres. Easy to say with hindsight, I know, but that is a disaster.

Rosberg ended up fastest with a soft tyre lap ahead of Petrov. But Vettel, Hamilton and Button did not use the faster soft tyres in that session.

Both HRTs qualify, with Liuzzi 0.5 seconds off the back of Glock's Virgin.

Webber was only 0.8 seconds off Vettel but because the midfield is so tight and all went out on softs he dropped out. But it was quite an untidy lap with a lot of understeer and, of course, the lack of KERS did not help.

Q2 is underway, Alguersuari heads out on track first.

Mike Gascoyne was not happy with Lotus' performance: "Disappointing gap to those in front, should have been closer, we have to get on top of the one lap pace in cool conditions"

Ferrari says: "Fernando and Felipe are ready to go, on soft used tyres"

So Alonso and Massa are hoping the tyres they used at the end of Q1 are still good enough for another flying lap.

Vettel is also out on softs so we are about to see what the Red Bull is capable of. His first lap was a 1:38.355 but he obviously had a problem.

Button goes fastest of all with a 1:34.662 on softs - the fastest lap of the weekend so far.

Hamilton is even quicker with a 1:34.486. That should be enough to make Q3.

Rosberg is attempting a hard tyre lap but looks set to fall outside the top ten. I'm sure he'll switch to softs for the end of this session.

Vettel's best was a 1:34.776 on hards but we know something slightly odd happened on his first lap on the soft fresh tyres.

Rosberg just sneaks inside the top ten but is told he will now swap to soft tyres for one more fast lap.

Force India are up for it: "Both cars in the garage...new boots and getting ready for next run to end this session.....2mins...here we go"

Schumacher, Rosberg, the Williams and Saubers all need to improve. Heidfeld has yet to set a time and has gone out on soft tyres.

Petrov stops on track with smoke coming from the airbox. He's fourth fastest but is out of the session having stopped. He will most likely start from tenth as a result.

There is just enough time for another run for all the cars but its going to get pretty busy.

Petrov stuttered to a halt after appearing to lose hydraulic pressure and the gearbox giving up. He hit the wheel in frustration and rightly so as he could have been on for a very good grid position.

The Renault is stuck in gear and the marshals have got a pick up truck and a crane to lift it off the track.

A big queue of cars has formed at the exit of the pits to try and get track position for a quick lap when the green light comes on.

And there it is as ten very hot F1 cars head out on track.

Perez and one of the Ferraris touch wheels as they jockey for position.

Massa leads the queue but Toro Rosso have opted not to attempt a lap.

Di Resta at the back of the queue just got over the line in time to start a lap.

Perez is out, Heidfeld is out, Alonso didn't bother with a time and goes through and di Resta makes it through even though he didn't complete his lap.

Schumacher also failed to make it through after a scrappy lap. Very disappointing as the car looks much quicker this weekend. His team-mate Rosberg just snuck through in ninth but had his last lap hampered by Perez.

Webber admits the car was not quick enough to make Q2: "Thought we had enough to get through," he said. "We weren't fast enough at the end of the day"

The green light is on for Q3. Button and Vettel are heading out, they still have two sets of soft tyres to use in this session.

Hamilton is staying in the pits alongside the rest of the top ten.

Vettel starts his lap and is quicker than Button in the first two sectors.

Button sets a 1:34.421 but that is put firmly in the shade by a 1:33.706 by Vettel for provisional pole position. It was the fastest lap ever set at this circuit, pretty impressive.

Hamilton is going to complete just one flying lap in this session.

Alonso is out on his flying lap as is di Resta.

As Vettel said in Malaysia: "Time to pull your trousers down and see what you have got" - the final flying laps of Q3 are coming up.

The Toro Rossos have set their single flying lap for this session and will stick with that. Alguersuari is ahead of Buemi in third and fourth but there are a lot of quick cars on track.

Alonso finishes his lap 1.4 seconds off Vettel. Rosberg beats Alonso, 0.5 seconds quicker.

Hamilton only manages third fastest behind Button and Vettel.

Vettel and Button come in early knowing Hamilton can't get in the mix now, so a bit of an anti-climax but Vettel and Red Bull have taken pole.

Vettel is still in the cockpit. A bit odd.

Vettel finally gets out the car as mechanics tend to it with leaf blowers to try and cool it down.