Lewis Hamilton enjoyed practice at the Mexican Grand Prix despite the "crazy" conditions on Friday.
The world champion was 11th and fourth fastest in the respective sessions at the Autodromo Hermanos Rodriguez in Mexico City.
Hamilton was shocked by how slippery the track was but said he enjoyed the tricky conditions.
"It was really challenging out there today - for everyone I think - but also a lot of fun," the Mercedes driver said.
"The track feels more like a go-kart track in the slow areas. It's crazy how slippery it is.
"Because we're so high up in terms of altitude, there's even less grip than in Monza, so the car was just sliding around.
"Of course, this is also because the track is new, so there is no rubber on it yet, but it's getting better and better the more we drive."
Hamilton's team-mate Nico Rosberg topped second practice after Toro Rosso's Max Verstappen was fastest in the opening session.
