Gabriele Tarquini set the fastest time in the final World Touring Car Championship practice session at Sonoma on Saturday.
The Italian's lap of 1m46.457s was a tenth of a second slower than Yvan Muller's fastest effort from the morning. Championship leader Muller took second in FP2, 0.286sec adrift of Tarquini's benchmark.
A large quantity of dust was brought onto the track by drivers dropping wheels off the track, and Lukoil SEAT driver Tarquini received a black and white warning flag for repeatedly cutting Turn 3A early in the session.
Ex-Formula 1 driver Tiago Monteiro's SUNRED machine ended the session in third, ahead of Tom Boardman, who was the first man into the 1m46s in the session to briefly top the timing screens shortly after the midway point.
After a puncture disrupted his acclimatization to Sonoma on Friday, Rob Huff was markedly closer to the top of the classification in FP2 and claimed fifth place. The third RML-prepared factory Chevrolet of Alain Menu completed the top six.
Tarquini's teammate Aleksei Dudukalo was seventh ahead of 2012 European Touring Car Cup winner Fernando Monje. Both men enjoyed spells at the top of the classification.
Several BMW runners suffered multiple spins. Stefano D'Aste appeared to encounter great difficulty negotiating Turn 2 without drama in his Wiechers-Sport entry, and Franz Engstler also pirouetted.
After an awkward inter-team collision in FP1, ROAL Motorsport teammates Tom Coronel and Alberto Cerqui confined their dramas to individual moments.
Pos Driver Team/Car Time Gap
1. Gabriele Tarquini Lukoil SEAT 1m46.457s
2. Yvan Muller Chevrolet 1m46.743s + 0.286s
3. Tiago Monteiro SUNRED SEAT 1m46.881s + 0.424s
4. Tom Boardman Special Tuning SEAT 1m46.885s + 0.428s
5. Robert Huff Chevrolet 1m46.987s + 0.530s
6. Alain Menu Chevrolet 1m47.080s + 0.623s
7. Aleksei Dudukalo Lukoil SEAT 1m47.136s + 0.679s
8. Fernando Monje SUNRED SEAT 1m47.224s + 0.767s
9. James Nash Arena Ford 1m47.308s + 0.851s
10. Tom Chilton Arena Ford 1m47.369s + 0.912s
11. Darryl O'Young Special Tuning SEAT 1m47.493s + 1.036s
12. Norbert Michelisz Zengo BMW 1m47.495s + 1.038s
13. Pepe Oriola Tuenti SEAT 1m47.593s + 1.136s
14. Franz Engstler Engstler BMW 1m47.828s + 1.371s
15. Tom Coronel ROAL BMW 1m48.089s + 1.632s
16. Alberto Cerqui ROAL BMW 1m48.471s + 2.014s
17. Alex MacDowall Bamboo Chevrolet 1m48.592s + 2.135s
18. Mehdi Bennani Proteam BMW 1m48.674s + 2.217s
19. Charles Ng Engstler BMW 1m48.967s + 2.510s
20. Stefano D'Aste Wiechers BMW 1m48.972s + 2.515s
21. Robb Holland Bamboo Chevrolet 1m49.712s + 3.255s