Esteban Gutierrez described his first day of winter testing as 'positive' as he finally got the chance to sample the Sauber C32.
Gutierrez completed 110 laps of the Jerez circuit, undertaking aerodynamic measurements, tyre and brake material testing and several long runs with high fuel loads, without any technical problems.
"It was a very positive day with 110 laps," he said.
"I had the chance to get to know the car and the tyres that are behaving quite differently. Because of this it was important to understand the warm-up characteristics and the behaviour on long runs with high fuel loads".
"It was very interesting to feel the progress - something that gets me up to speed. I’m positive about the new car and I immediately felt comfortable in it."
Gutierrez returns to the car for his second day of running tomorrow.