Does F1 still need in-season testing?

On Tuesday, the first full-blown in-season Formula 1 test since September 2008 kicks off at Mugello. Save for last year's young driver days in Abu Dhabi, there has not been a single test during a campaign since then, save for the permitted straightline runs and filming days, both of which allow only strictly limited mileage. Since F1 testing's peak in 2006, when 61 drivers completed well over 400,000 km and not far off 100,000 laps, the sport has been utterly transformed.

The test ban was introduced ahead of the 2009 season. This year, pre-season running was restricted to a maximum of 12 days per team, with the three-day Mugello test bringing them up to the 15-day mark that has become the norm in recent seasons. Yet, for all that, cars still develop at an incredible rate, even though the three hours of running on grand prix Fridays is the only regular chance to try new parts.