Red Bull's Christian Klien topped the team-sheets on the second day of testing at Barcelona.

The Austrian team had both Klien and newly signed test driver, Robert Doornbos, on duty as four more teams joined McLaren and BMW, who began testing on Monday.

Whereas yesterday all drivers were running V8s, today, several drivers, including the Red Bull duo, were using V10s, hence the disparity of lap times.

McLaren's Alexander Wurz was the quickest of the V8 powered drivers, the Austrian finishing second overall, just 0.187s off Klien's time. After the transmission problems that blighted the first day of testing, today ran relatively smoothly for the Woking driver, who was joined by Pedro de la Rosa.

Tomorrow will see a pre-scheduled break in McLaren's test programme, with track action beginning again on Thursday. Juan Pablo Montoya will be testing on both Thursday and Friday. Pedro will be present on Thursday, with Gary Paffett returning to the cockpit on Friday, after his test on Monday.

The newly launched Toyota TF106, was debuted by Jarno Trulli and Ricardo Zonta, the Italian complaining of handling problems. That said, the two Japanese cars finished third and fifth quickest, sandwiching de la Rosa.

Toro Rosso - making its track debut - ran Tonio Liuzzi in the 2005 Red Bull car, albeit fitted with a modified V10. The Italian finished sixth quickest, over 2s off the pace.

WilliamsF1's Nico Rosberg was joined by newly-crowned World Touring Car Champion, Andy Priaulx. The Grove cars - running in their 'Winter livery' - were both fitted with the new Cosworth V8 and running on Bridgestone rubber.

The German was the quicker of the two, albeit 2.8s off the pace.

BMW continued with Nick Heidfeld in the BMW P86 V8 equipped Sauber C24B. In the morning, the engineers focused on data acquisition runs particularly for the engine. However, due to a leak in the fuel rail, work was stopped early in the afternoon.