Hello and welcome to ESPNF1's live coverage of first free practice for the German Grand Prix. After Fernando Alonso rocked the Red Bull boat with victory at Silverstone - and team orders to Mark Webber threatened to rock it even further - the rest of the grid will be looking to put even more pressure on the championship leaders.

There's been another change to the grid this weekend following Daniel Ricciardo's debut for HRT in Britain too; Karun Chandhok replaces Jarno Trulli at Lotus for this race as Tony Fernandes and Mike Gascoyne look to evaluate the progress made by the Indian who has only had limited running in previous practice sessions.

And on top of that, we're back to the previous engine mapping and off-throttle blown diffuser configurations which were seen at the European Grand Prix in Valencia. McLaren's Paddy Lowe says he hopes that will see the team close up on Red Bull and Ferrari once again, having said "we probably went backwards relative to them by 0.7s or 0.8s".

As always, we want to hear from you today. If you've got an opinion or a question that you wish to send us you can do so using the link above or via Twitter @ESPNF1_live.

Mike Gascoyne on Twitter: "Morning from an overcast paddock at the Nurburgring. Forecast saying should stay dry so fingers crossed."

The teams were fearing the worst yesterday when a heavy downpour hit the circuit, but any dry running could end up being fairly redundant as the forecast for the weekend is very mixed indeed.

Paul emails in to say: "Now that Red Bull have their 50% throttle back, I reckon Mark will have the rub over Seb this weekend."

A couple of driver changes for you for this session: Nico Hulkenberg has taken over Paul di Resta's Force India, while Narain Karthikeyan is in the HRT in place of Tonio Liuzzi.

The session is underway, and Heikki Kovalainen is the first man out on track.

Felipe Massa goes round for a second installation lap to conduct a straight-line aerodynamic test on the pit straight.

Button is running a lot of aero paint on one half of his rear wing, while Hamilton locks up heavily on his out lap.

Only Glock and Massa are out on track at the moment.

Chandhok joins them but no times set yet.

Nizam emails in to say: "Here's wishing that another team other than Red Bull takes the top step of the podium, to keep the championship open. Ferrari looks best placed to carry on the momentum."

Lotus (MyTeamLotus) on Twitter: "All teams have two development-spec version of the soft compound tyre to try during today"

Helmut Marko and Mark Webber have a chat in the Red Bull garage as D'Ambrosio misses the apex at the first corner as he starts a flying lap.

Williams (WilliamsF1Team) on Twitter: "Today we are running new rear wings on both cars as well as a new front wing on Rubens' car ... And we'll also be doing some dry/wet set-up work"

A bit of a strange moment as the glass from Chandhok's left wing-mirror falls out under braking for the turn seven hairpin.

We still don't have a timed lap, but we have got Heidfeld pushing fairly hard...

...and he sets the first time of the race weekend, a 1:38.313.

Perez also sets a time, but is quite a way off Heidfeld's pace with a 1:40.730

Heidfeld improves to a 1:37.983 and Alguersuari does a 1:40.333

Rosberg goes second quickest with his first timed lap on a 1:38.170

We've now got times from Heidfeld, Rosberg, Perez, Alguersuari, Kobayashi, Barrichello and Ricciardo, although the latter two are not representative of any pace.

Rosberg improves significantly on his second lap to go fastest - 1:35.751

Paul asks: "Do you think it is Ferrari who has done the most protesting (behind the scenes) without looking like the normal whining team they are, and is this why they benefitted the most the other weekend?"

Obviously we don't know what goes on behind closed doors, but I think it's more a case of Ferrari staying quiet because they were comfortable with running the car without the off-throttle blown diffuser. They've also heavily updated the car recently and appear to be pleased with it in most conditions due to downforce created from other areas, and is therefore not as concerned by the diffuser blowing as Red Bull and McLaren.

Hamilton goes fastest, a 1:33.576 putting him 1.4s quicker than Rosberg.

Barrichello and Kobayashi both lock up and run wide at turn one, as Perez did earlier.

Hamilton going quickly once again, setting fastest first and second sector times

And Hamilton improves to a 1:32.996, over two seconds quicker than Rosberg now. Only 11 drivers have set timed laps so far, but Alonso, Webber and Vettel are now out on track too

Hamilton pits after that run on soft tyres. Vettel is also on the softer tyre as he starts his first flying lap

Vettel's first lap is a 1:37.620, 11th fastest for now

Petrov has gone seventh, and he is running the normal front-exiting exhaust system on his Renault, but Heidfeld is testing a more conventional Red Bull style exhaust this morning.

Vettel improves to fourth quickest, with Webber now second but over 1s slower than Hamilton

Webber locks up in to the Dunlop hairpin but just keeps the car out of the gravel

Button goes fourth quickest, before Vettel goes fastest on a 1:32.760

A big moment for Schumacher as the rear end almost gets away from him at high speed, but he manages to catch the car and keep it on track.

Chris emails in to ask: "Rosberg seems to be just pumping out the laps. Is he testing or running heavy fuel load?"

All of the teams will be testing new parts this morning, and will run a fairly heavy fuel load in order to do so. Mercedes is regularly doing a lot of running on a Friday, and both Rosberg and Schumacher are the busiest drivers so far. Mercedes also has a new exhaust system first run at Silverstone, and will be evaluating the effect of the new off-throttle blown diffuser spec.

Alonso goes quickly on the harder tyre - which is the medium compound this weekend - but is still a second slower than Vettel.

Brian asks: "Why is Red Bull running softs?"

With the development softs available to all the teams to hand back today, it's a good opportunity to do extensive running on soft tyres.

We're still yet to see a timed lap from Karthikeyan or either Virgin.

And as I type, Glock does his first lap but is 11 seconds off the pace, and Karthikeyan starts a lap. Chandhok, incidentally, is 8.7s off the pace at present as he gets up to speed in the Lotus running slick Pirelli's in anger for the first time.

On track at present are Sutil, Alguersuari, Barrichello, Kovalainen, Maldonado, Hulkenberg, Ricciardo, Glock and Karthikeyan

Alonso joins them, as replays show Glock taking too much kerb in the final chicane and really bouncing over the inside.

Alonso is out on the experimental soft tyre now, so we'll see how close he can get to Vettel's current headline time of 1:32.536.

Right on cue, a fastest first sector for Alonso. Rosberg is also out on soft tyres

Alonso completes his lap and is second quickest - 0.038s slower than Vettel, who is also going quickly

Vettel improves his time by 0.002s, so the quickest time is now a 1:32.534. The championship leader is, of course, sporting a new helmet design for his home grand prix.

Alonso is going quicker again, and he sets the fastest time, a 1:32.037 - half a second quicker than Vettel with half an hour of this morning session to go.

Webber improves to third quickest, 0.07s slower than Vettel in second.

Schumacher has to catch the rear end of his Mercedes under braking in to turn one.

Massa is fourth quickest, 0.7s slower than his team-mate who has just improved to a 1:31.981

Webber goes second quickest on a 1:32.217. Good to see so much soft tyre running in this session

Chetan asks "Why is Karun not racking up the laps. He is the one who needs them the most?"

And the answer from Lotus (MyTeamLotus) on Twitter: "Karun and engineer Gianluca having a chat about some minor tweaks and settings before he heads back out again"

Heidfeld's car looking very hot as it is wheeled back in to the garage, testing the new rear-exiting exhaust system.

Vettel improves his best time but stays third on a 1:32.268

Glock is told he has some slight front wing damage after his heavy clout of the kerb earlier in the session. Schumacher and Perez both lock up in to turn one.

Schumacher runs wide at the turn seven hairpin after losing the rear end and waves to the fans as he comes close to the barrier. His supporters probably didn't expect to see him so close the the grandstand, but no damage and he continues.

Chandhok is slowly improving, a 1:40.251 putting him 21st now, four seconds slower than his team-mate Kovalainen.

In the HRT, Karthikeyan is currently 0.2s quicker than Ricciardo who has replaced the Indian indefinitely.

Most cars back in the garage now, with only Sutil, Hulkenberg, Kovalainen, Maldonado, Chandhok and Glock on track.

The engine cover is off Massa's Ferrari and mechanics are working on the back of the car. No word as to what the problem is yet.

Alonso, Webber and Vettel join the circuit on the medium tyre.

Ten minutes to go and Alonso locks uop in to turn one - apologies he is on one of the soft compounds again, not the medium as Vettel and Webber are.

Alonso was set to improve his time but has to back off after the final chicane due to a Renault in front of him. Somewhat predictably there's a little wave of his right hand in anger.

Massa is still in the pits, while Alonso, Vettel, Webber, Hamilton and Button circulate. Incidentally, the McLaren's are 1s and 1.6s off the pace respectively.

The only word from Ferrari is "time for a quick change on Felipe's car". Very quick it needs to be, as he is still in the pits with two and a half minutes to go.

Hamilton plays with the dials on his steering wheel before winding up for a flying lap on the medium tyre with his team-mate Button close behind.

Massa leaves the pit lane finally after Ferrari admits "The change on Felipe's car requested more time than expected"

Buemi puts two wheels on the grass as he hits the brakes for turn four and he flies sideways through the gravel at high speed. He's fortunate not to roll the car.

The serssion is over, Alonso was on a flying lap just as Buemi went off and he went even quicker with a 1:31.894.

Vettel takes off his gloves as he gets wheeled back in to the pits having set the third fastest time behind Alonso and team-mate Webber. Massa was fourth quickest, 0.4s behind the Red Bull pair and 0.787s behind Alonso. Hamilton is another 0.4s slower with Button over half a second further back. All of the top 12 times were set on the experimental soft tyre.

So Ferrari shows that it still has the pace to challenge Red Bull even after the off-throttle diffuser regulations have been reverted. Can McLaren close that gap too? Alonso will be hoping for more of the same in FP2. Thanks for all your messages and don't forget to join us again in two and a half hours.