Updated on November 5th, 2012: From BARB:
1 – 723k – Live Italian Grand Prix (Sunday, 11:30)
2 – 404k – Live Italian Grand Prix: Qualifying (Saturday, 12:00)
3 – 110k – Live Italian Grand Prix: Practice 3 (Saturday, 09:45)
4 – 52k – Fast Track (Saturday, 11:29)
5 – 50k – Live Italian Grand Prix: Practice 2 (Friday, 12:45)
6 – 47k – The F1 Show (Friday, 17:00)
7 – 47k – Porsche Supercup: Europe (Saturday, 11:15)
8 – 43k – Live Italian GP2 Feature Race (Saturday, 14:35)
9 – 35k – Live Italian Grand Prix: Practice 1 (Friday, 08:45)
10 – 32k – Legends (Sunday, 16:05) (Sunday, 16:05)
The channel reached 2.522 million people, which is slightly higher than the Hungarian Grand Prix back in July, which reached 2.439 million people. Excluding Germany, which was open to all Sky and Virgin Media viewers, the channel had it’s highest reach for a European round since the Bahrain Grand Prix in April which reached 3.419 million people.
Outside of the Sky Sports F1 channel, the Italian Grand Prix highlights made BBC One’s top 30, the programme recording an official average figure of 3.67 million viewers, the 24th highest programme on BBC One that week. This compares with an overnight figure of 3.57 million viewers, so the programme timeshifted only 100,000 viewers which is unsurprising as sporting events rarely do timeshift in large proportions.
Back over to Sky, and the speedway made two of their top 10’s, with the Elite League Speedway being watched by 74,000 at 19:30 on Sky Sports 3 on Wednesday 4th September, while the Grand Prix Speedway was seen by 50,000 the following Saturday over on Sky Sports 4.
Updated on November 5th, 2012: Now that we have the top ten, the Friday practice figures are low, particularly first practice which is half the usual figure. For whatever reason, the Belgian and Italy double bounce did not do well for the Sky F1 channel, the Paralympics being one possible reason. It is also disappointing to see no GP3 figures here given the very exciting race two on Sunday morning.
Motorsport Broadcasting 
How do you work out that the channel reached 2.522 million people?
BARB posts all of the weekly reaches here: http://www.barb.co.uk/report/weekly-viewing?_s=4 (go to Sep 03-Sep 09 on the left hand side)
To quote their definition of reach: “the number or percentage of people who have viewed the channel within the week for at least three consecutive minutes.” – so 2.522 million people watched the Sky Sports F1 channel for at least three consecutive minutes in that week.