Max Verstappen highlighted the low-grip conditions facing the drivers at the Mexican Grand Prix circuit, following his spin in free practice one.
The Dutchman was one of a few drivers to fall foul of the reduced grip at the Circuit Hermanos Rodríguez.
With free practice two being earmarked for Pirelli tyre testing, drivers were pushing the limits in the first practice session to complete their own testing schedules.
Midway through the fast Turn 11 on a Soft-tyre run, Verstappen lost control of his Red Bull car and spun into the tarmacked run-off areas, but avoided damaging his car.
Viewed by others:
Verstappen: Small 'moment' triggered spin
Speaking after the practice sessions, Verstappen put the error down to a sharp reduction in surface grip off-line.
"I had a small moment, but as soon as I got just next to the ideal line it was like driving on ice. Eventually I lost the car and stepped on the brakes," Verstappen commented on his official website.
He continued to explain that the official Pirelli test made comparisons more difficult than usual.
"On the soft tyres it went fine, but we only drove one run on those. In the second free practice we had Pirelli's tyre test and that made everything a bit trickier and more unfamiliar, just like last weekend. The hard tyres are a bit more treacherous.
"We have not been able to gather much information yet, but looking at what we have been able to try, everything is working quite well."
F1 Podcast: What does Dietrich Mateschitz's death mean for Red Bull?
RacingNews365.com F1 journalists Dieter Rencken and Michael Butterworth discuss the key issues from the United States Grand Prix, including what Dietrich Mateschitz's death might mean for the future of Red Bull in F1.