From BARB:
1 – 58k – Live Barcelona Testing: Day 3 (Saturday, 14:00)
2 – 47k – Live Barcelona Testing: Day 4 (Sunday, 14:00)
3 – 47k – Day 1: Barcelona Test 2 (Thursday, 21:00)
4 – 43k – The F1 Show (Friday, 16:30)
5 – 42k – Car Unveiling: McLaren (Saturday, 16:30)
6 – 41k – Ted’s Notebook: Barcelona Test 2, Day 1 (Thursday, 21:18)
7 – 38k – The F1 Show (Friday, 20:00)
8 – 34k – Barcelona Testing: Day 1 Replay (Thursday, 18:30)
9 – 32k – Live Barcelona Testing: Day 1 (Thursday, 14:00)
10 – 29k – Ted’s Notebook: Barcelona Test 2, Day 4 (Sunday, 21:23)
Most of the above I have summarised here from the overnight ratings, the only note being is that a lot of people do not seem to watch The F1 Show live or on the day and instead choose to watch it on Saturday or Sunday, the show timeshifting a fair bit in the official BARB ratings.
The channel during the testing week reached 1.12 million people across the week, by far the highest reach of the year. In comparison, the channel’s first weekend on air last year reached 1.76 million viewers. Although the reach there is lower, I think Sky will be pleased overall with the ratings for testing, and I can see it returning in 2014.
Motorsport Broadcasting 
My Sky signal crapped out through no fault of my own during the first F1 Show timeslot, I presume this is an anecdote rather than data though.