The top ten finishers have had their cars weighed and the rest of the pack have declared their fuel levels for tomorrow’s Spanish Grand Prix. From the weights of the cars we can work out how much fuel each car is carrying simply by deducting the minimum car-and-driver weight (605kg) from the total figure, and from this we can work out how many laps of gas they are each holding in their tanks. From this, we can allow one laps worth of fuel for grid forming and one more as a margin, and we can predict when the drivers will stop.

According to Williams (via F1Minute), fuel consumption around Circuit de Catalunya is about 2.27164 kilograms/lap.

Spain 2009 Post-Qualifying Car Weights		Car Weight Kilograms	Fuel Weight Kilograms	First Stop Lap
1.	Jenson Button Brawn	646	41	16
2.	Sebastian Vettel Red Bull Racing	651.5	46.5	19
3.	Rubens Barrichello Brawn	649.5	44.5	18
4.	Felipe Massa Ferrari	655	50	20
5.	Mark Webber Red Bull Racing	651.5	46.5	19
6.	Timo Glock Toyota	646.5	41.5	16
7.	Jarno Trulli Toyota	655.5	50.5	20
8.	Fernando Alonso Renault	645	40	16
9.	Nico Rosberg Williams	668	63	22
10.	Robert Kubica BMW	660	55	22
11.	Kazuki Nakajima Williams	676.6	71.6	30
12.	Nelson Piquet Jr. Renault	677.4	72.4	30
13.	Nick Heidfeld BMW	676.3	71.3	29
14.	Lewis Hamilton McLaren	683	78	32
15.	Sebastien Buemi Scuderia Toro Rosso	678	73	30
16.	Kimi Raikkonen Ferrari	673	68	28
17.	Sebastien Bourdais Scuderia Toro Rosso	669	64	26
18.	Heikki Kovalainen McLaren	657	52	21
19.	Adrian Sutil Force India	675	70	29
20.	Giancarlo Fisichella Force India	656	51	20

From the table we can see that Jenson Button was relatively light on his final run, indicating that the other teams have indeed started to close the gap up to the Brackley squad. Sebastian Vettel and Felipe Massa did quite well with slightly heavier cars than those immediately around them, and both Red Bulls are on the same fuel level, although unless one driver falls particularly far behind the other in the opening laps, it is unlikely they will pit on the same lap.

Also worthy of a mention is Fernando Alonso, who is running light and will hope to make up some places at the start. Although it highlights how much his Renault is under-performing at the moment. Nico Rosberg is particularly heavy and will run a long first stint, as will many of those behind him. Lewis Hamilton is the heaviest driver while team mate Heikki Kovalainen is obviously looking to make up some places at the start as he is comparatively light.

• The qualifying results can be viewed here: Spain 2009: Qualifying Result.
• The live qualifying notes can be viewed here: Spain 2009: Live Qualifying Notes.
• The grid (inclusive of penalties) can be viewed here: Spain 2009: The Grid.
• The qualifying report can be viewed here: Spain 2009: Jenson Button Claims Pole On Final Last Gasp Attempt.