Good morning and welcome to ESPN's live coverage of the final free practice session of the 2012 season. One final hour to prepare for qualifying, with every chance of rain affecting that session later today

Lewis Hamilton was the man to set the pace throughout Friday as he topped both FP1 and FP2, and he admits McLaren is "certainly looking strong". For the title hopefuls, Sebastian Vettel was 2nd and Fernando Alonso 5th in both sessions

While rain could mix things up this afternoon, it looks like we might just squeeze qualifying in before any wet weather comes, and that makes this session crucial. Alonso said that he was struggling with the balance of his Ferrari yesterday, and that "there is still a lot of work to be done with the engineers"

The latest weather report from our man Laurence in the paddock is: "A bit muggy and quite a bit of cloud cover, but the sun is just poking out". It's warm again, with air temperature at 27C and track up at 32C

We may only have one hour of running this morning, but we still want to hear from you with your questions and comments. You can get in touch either by emailing us using the link above or via Twitter @ESPNF1

While we will be talking about the weather a lot during the next few hours, we're (pretty) certain we'll have a dry FP3. The teams' weather radar says no rain for 30 minutes

I flagged up Alonso's complaints with balance yesterday, but based on the long runs in FP2 I wouldn't be sitting all that comfortably if I was Vettel, either. The Red Bull seemed to be a bit off the pace, with McLaren fastest and Lotus and Ferrari close behind and Mercedes and even Force India near Red Bull's times

That last it of information needs marking with an asterisk, though, as we don't know the fuel loads in each car, but it's usually a pretty good barometer...

It's looking pretty breezy at the circuit now as more cloud cover blows in. Weather can change very quickly here...

The weather radar shows rain to the north of the circuit but it's passing comfortably away from the track. 'Despite gathering clouds, no rain is expected yet' says the forecast

Time to switch our attentions to the track rather than the skies; two minutes until FP3 begins and Alonso is all smiles as he prepares himself in the Ferrari garage

The session begins with a queue of cars waiting to head out on track

The lack of sun has really kept the track temperature down compared to yesterday. We saw 50C during FP2 but these lower temperatures should see the teams struggling a bit less

I say struggling a bit less - it was so hot yesterday that the tyres were overheating and just sliding on the track surface. Hamilton said it felt like the tyres were "melting" as he circulated

Practice starts taking place at the end of the pit lane, Vettel the latest to do one and Alonso overtakes him on the run down to turn four

Glock also crossed the pit lane exit line as he came out for his installation lap - the stewards may fine him for that one

Ravin asks: "With such different conditions throughout the weekend, how are the tyres going to hold up? Degradation? A 2-stopper or more maybe?"

Based on yesterday's heat we would definitely be looking at two or maybe three stops, but even if the race is dry temperatures are expected to be much lower. With the hard and medium tyres available we think we're looking at a one or perhaps two-stop race

Rosberg sets the first time of the day with a 1:20.153 and Schumacher follows it with a 1:22.570

Next time round both drivers are more on the pace and Schumacher goes fastest with a 1:15.034 - just 0.274s ahead of Rosberg

It's only the two Mercedes' and Kobayashi out on track at the moment. All on hard tyres.

Button has said on the radio that the current track temperatures means "there is amazingly good grip"

Kobayashi sets a 1:15.527 for third quickest

James emails in to ask: "My question is does Kobayashi have a chance for a drive with one of the lesser teams in 2013?"

Unfortunately it doesn't appear so. It's not that Kobayashi's done a bad job - performances like Japan were very impressive - but to get a seat at a lesser team he'd need to bring substantial money and he doesn't have it. He's said sponsors is something he's working on for 2014

Kobayashi goes second fastest with a 1:15.158

Vinay says: "Massa is looking strong in the past few races. I think he will give Alonso a run for his money next season."

He has looked very impressive since the summer break, but Massa knows his role at Ferrari and he's the number two driver

Looks like an engine failure for Raikkonen - smoke pouring out of the back of the car

Raikkonen was at full throttle in sixth gear on the run towards turn four and the engine let go. That's no running for him in FP3 but it may not mean he has to take use a ninth engine - he should have one of his previous eight available for the race

Button goes quickest with a 1:14.419, 0.133s ahead of Hamilton

Grosjean will have to do all the work for both drivers this weekend now, with Raikkonen having had little running in FP1 too

Senna runs wide at turn one and makes use of the concrete run-off area. He'd locked up and then got off the brakes to save that set of tyres

Hamilton goes quickest, but not for long as Button again improves with a 1:13.917

Button was slower than his team-mate in FP2 because he ran a different rear wing. They both have the same high-downforce wing on today

Hulkenberg tells Force India on the radio: "This is a totally different car today; much better". That is probably as simple as the lower track temperature giving him more grip

Hamilton improves but stays second, will Button then responds with a 1:13.858

Senna says he has some vibrations on his tyres, which could be a result of his lock-up in to turn one

A lot of lock-ups today, Button and Hamilton both have been at Bico de Pato, while Vettel does in to turn one as well

Maldonado is third fastest but 0.569s off the pace

Vettel goes third with a 1:14.135

Everyone still on the hard tyres

Anton emails in to say: "With the cooler temperatures that are predicted for qualifying later today and tomorrow's race, could we be looking at Mercedes possibly throwing another spanner into tomorrow's world championship decider? They've been running reasonably well on their long runs, and with the temperatures staying fairly low, this could work to their advantage since traditionally they've brought their tyres up to temperature much faster than other teams. Would definitely be nice to see Schumacher bow out with a podium if the cards fall his way."

Mercedes indeed looked stronger on long runs, but I think Schumacher's best chance of a podium will be if it rains tomorrow

Vettel goes second with a 1:13.924 having set the fastest middle sector. The time he lost was in the final sector

Webber improves to a 1:14.263 wand fourth fastest

Altaf asks: "Can kimi rejoin in FP3 ??? Will he get in penalty if he use fresh engine ???"

We've had an email from Sriraj on the same topic. No Kimi can't rejoin in this session as it takes much too long to change an engine. He shouldn't get a penalty as it's one of his eight race engines that he should be able to use (he will get a penalty if he had to take a brand new engine which would be his ninth of the season), but that's providing Lotus can change the engine in time before qualifying starts

Alonso's first timed lap is a 1:14.863 - just 0.1s slower than Massa

On the topic of the Ferrari drivers, Vrijilesh says: "Massa was number 2 to Kimi in 2008 as well. But the way he stepped up and fought till the heartbreak moment was champion stuff. Alonso needs to be wary next year"

But Massa challenged for that title because Raikkonen had such a poor season as his interest appeared to wane following his title. Can anybody realistically see Alonso suffering a similar slump in form?

Massa improving on this lap and he goes fourth - 0.360s off Button's best

The two Ferraris are running line astern and Massa got a nice tow from Alonso at the end of that lap

Prashant asks: "What if massa secures podiums in the starting of next season, will he become no. 1 driver for ferrari?"

It's unlikely, because you'd assume Alonso would be in the mix too. If for some reason Massa was in the championship battle around the half-way mark and Alonso wasn't, then yes I believe Alonso would be expected to try and help Massa's challenge

Massa improves once again to a 1:14.055

Button following Hulkenberg closely in to turn one and Hulkenberg locks up heavily

@Lotus_F1Team on Twitter: "Looks pretty certain that #Kimi's engine reached the end of its life in the limelight. Loss of oil pressure in the data gives the game away"

@RenaultSportF1 on Twitter: Spare engine is ready to go once the car gets back... change can be done during break between sessions @Lotus_F1Team

22 minutes to go and Vettel's just started another flying lap on hard tyres. He's 0.1s off through sector two

Vettel ends that lap 0.3s off the pace. Interestingly it's looking a bit gloomier over the circuit

Schumacher starts a flying lap on the medium tyres

Schumacher's had his lap ruined by a spinning Senna

Senna had dropped it at the final corner having run wide and he spun back across on to the track as Schumacher was coming. Schumacher avoided him to the inside

Senna was very wide and properly off the track, and I think he actually dragged the car in to a spin to avoid the barrier on the outside

Siddhesh asks: "Interesting comment from Massa earlier, about wanting to win with Alonso coming second. Do you think Ferrari might allow him to, assuming that Alonso is out of Championship contention?"

If Alonso is second behind Massa then no, Ferrari would switch them because you never know what might happen on the final lap - look at Hamilton in 2008. If Alonso finished second and Vettel had a problem and crawled home sixth then Vettel would still be champion, but Alonso would have been if he had won

Rosberg on the medium tyres and he improves his first sector time. We haven't seen many improvements for a while, but Rosberg goes 0.268s off the best time

Luis emails in to ask: "Is it sure quali will begin wet?" No, it's far from certain. Qualifying is actually expected to be dry, but there's a threat of rain

Empty track at present as drivers prepare for medium tyre runs

Raikkonen is sat trackside watching the session, and Vergne heads out to pierce the silence

Nambirajan asks: "Looking at Alonso's career, He has to have a No. 2 driver as his team mate. Do you think he can perform well if they are on same terms? Is it possible Massa's slump in form for the first half due to his team mate getting new aero parts first."

I'll tackle this in three parts. Firstly, Alonso's year at McLaren shows that he's far from comfortable when his team-mate has equal footing. Secondly, you have to earn the right to be a number one at a team, which Alonso did at Renault and that allows him to do the same elsewhere. Thirdly, it was more a case of Massa struggling to drive round the problems the car had - a sign of Alonso's class - but as the car improved, so did Massa's performances

Hulkenberg goes quickest on the medium tyres with a 1:13.623

Di Resta improves by 0.8s on the medium tyres and goes fastest with a 1:13.617. Not for long, though...

Button goes comfortable fastest with a 1:13.192

Grosjean goes second with a 1:13.420, while Massa receives a tow from Alonso once again but only goes fifth

All these times are on the medium tyre

Webber is just 0.008s off Button through sector two, but the Red Bull is slower in sector three and he ends up second - 0.2s slower

Hamilton starts his final lap while Alonso goes sixth but half a second slower than Button

Di Resta improves his best time to a 1:13.515

Hamilton was stuck behind Webber at the end of his flying lap and can only go fifth - 0.341s slower than Button

It's the second shortest lap of the season, and with 20 cars on track traffic is a problem

Button with the fastest first sector

Vettel's only just gone out with 90 seconds to go, so he'll be the last man to set a representative qualifying time

Preetam asks: " Do u think any of Force India's car having podium finish...today they are looking strong..."

Force India does look strong, but I think its long run pace isn't quite good enough to challenge for the podium

Button improves his best time to a 1:13.188

Petrov was heavily blocked by Hulkenberg and raises his finger at the Force India at Juncao

Vettel's improving and fastest through sector two...

Vettel loses time in the final sector and goes second, just 0.057s slower than Button. Hamilton improves too but only to fourth - 0.201s off the pace

Both Force Indias beating both Ferraris in that session, with Alonso ending up half a second off the pace down in eighth

There was clearly more pace in the McLaren, which had enough fuel in the car to do a number of flying laps at the end, and both drivers improved on their final lap despite having used the best of the tyres

Button the fastest man in this final session, and that makes it a McLaren clean sweep of practice here in Brazil. It also marks the end of practice for 2012, just qualifying and the race to go and we'll know the 2012 world champion.

For the Schumacher fans - he won't take part in another Formula One practice session, and he's about three hours of track time away from retirement. He ended that session in 15th and 1.1s off the pace, although he did do his flying lap early on the mediums and was hampered by Senna's spin

We'll take a short break ahead of qualifying, but live commentary will be back in 90 minutes to bring you all the coverage as the final grid of 2012 is decided. It's sure to be a crucial session and rain could mix things up too. Don't miss it.