Canada's Neil Young claimed that rust never sleeps. Rest assured, neither does Formula One.

Since the season ended, just over five weeks ago, the drivers will have enjoyed a little 'private time', at least those that weren't chasing drives for 2007 will have, in addition to carrying out promotional work for teams and sponsors.

However, back at the factories the engineers and boffins will have been working flat-out, looking for that extra hundredth of a second.

Today sees the first of three major tests that will bring 2006 to a close, as we all look ahead to the new season, and, in the absence of Michael Schumacher, a new era.

This week's test at Barcelona, to be followed by two further tests at Jerez, will see a few drivers make their maiden appearance with new teams, including Anthony Davidson for Super Aguri, and Mark Webber at Red Bull, though we will have to wait until January before we see Fernando Alonso in the McLaren and Kimi Raikkonen in the Ferrari.

However, the biggest change, and the main focus of interest as we await the arrival of the 2007 cars, is the fact that, following the withdrawal of Michelin, a number of teams, including World Champions Renault, now have to make the switch to Bridgestone rubber.

"To a very large extent, our running will deal with learning and adapting to the true characteristics of the Bridgestone tyres," admits Renault's Pat Symonds. "However, the fact we will be using the same engine architecture next year means it is also cost-effective to run components from next year's car during these sessions, for reliability testing. We will be taking full advantage of that opportunity.

"We have received a lot of data from Bridgestone," he continues, "which has been applied to our computer modelling in order to understand the basics of how the car set-up need to be altered to get the best out of the tyres. Factors such as weight distribution and the aerodynamic characteristics of the car need to be re-assessed to determine how to best use the Bridgestone tyres.

"No amount of mathematical data can explain the subtleties of the tyres," he adds, "and especially of the tyre compounds. We need to run on track in order to understand how to best use the tyres over a stint, what driving style they require, and their general strengths and weaknesses. The majority of our nine days will be spent trying to get a handle on these characteristics."

Make no mistake, though we are not seeing the 2007 cars, nor the full line-ups, all three tests in Spain are critical, and should give us an idea as to how things are shaping up for the new season.

Pitpass will bring you all the times and a full report at the end of each day's action.