Jerez:Nick Heidfeld was fastest on Tuesday on the opening day of Formula One's final testing session of 2007.
The BMW Sauber driver had a best time of 1 minute, 19.042 seconds from 78 laps around the 4.428-kilometer (2.751-mile) Circuito de Jerez. Honda's Jenson Button was next at 1:19.155, and McLaren test driver Pedro de la Rosa was third fastest in 1:19.712.
World champion Kimi Raikkonen of Ferrari had the fourth best time at 1:19.712 from 48 laps.
The man Raikkonen replaced seven-time champion Michael Schumacher was scheduled to test with the Italian team on Thursday and Friday.
Schumacher was fastest in winter testing at Barcelona last month in the 38-year-old German's first spin behind the wheel of a Ferrari since retiring in 2006.
McLaren driver Lewis Hamilton, who finished second to Raikkonen in the driver's standings after leading for most of his rookie season, is scheduled to drive Wednesday and Thursday.