Max Verstappen, the 16-year-old son of ex-Formula 1 racer Jos, emerged fastest from his first day of testing in a Formula 3 car.
Verstappen comfortably topped Wednesday's times at the Valencia circuit with a German Formula 3 Cup car run by the series' top team Motopark.
Motopark is using the series' spec VW Power Engine, which is more powerful than the engines used in the European and British F3 championships, but Verstappen was also much faster than any of the other German F3 Cup cars present.
The Dutchman, who is a World Karting champion, is expected to compete in the Formula Renault Eurocup next season and has been testing FR2.0 cars extensively, most recently with Josef Kaufmann Racing.
"It was a great day," said Verstappen. "The F3 car suits me perfectly and from lap one I had good pace.
"I was able to adapt rather quickly to the car so I felt confident to push, but I honestly did not expect to be fastest.
"The F3 is a bit heavier but is an absolute joy to drive. Working together with my engineer and the whole team was a great experience. It's all very professional and a step up from FR2.0, as there is a lot more data and attention to detail needed."
The test continues on Thursday.
DID YOU KNOW?
The F3 career of Kevin Magnussen, whose father Jan was replaced by Jos Verstappen in the Stewart F1 line-up in 1998, also began with Motopark. He finished third in German F3 with the squad in 2010.