DTM Champion Marco Wittmann was left to reflect positively as he received his maiden Formula 1 outing with Toro Rosso on Wednesday.
Wittmann was given the prize test from BMW as a reward for winning last year's title in the German series.
Wittmann was scheduled to drive for Toro Rosso earlier this year at Imola but wet weather caused the private test to be cancelled.
Wittmann's outing was rearranged for the Red Bull Ring, where he completed 158 laps on his way to the fourth fastest time.
"This has been an amazing experience for me," said Wittmann. "I was surprised at the power of the car; if I compare it to DTM, it’s got quite a lot more power!
"I enjoyed the whole day, which was trouble free, so I was able to do a lot of laps. I’m happy with my day, I hope the team is too."
Toro Rosso chief race engineer Phil Charles said that the squad was impressed by Wittmann.
"We’ve had a very productive day, completing a high number of laps, with Marco making no mistakes and impressing us all with his approach and feedback," he said.
"There was a short time of adjustment as he got used to the difference in braking from the DTM car to a Formula 1 machine. He then settled into a rhythm, as we started off our programme with a series of long runs.
"After that, it was time to proceed with the items on our test agenda; aero, tyre and set-up work, with some performance runs in the middle of the day, mainly for the driver’s benefit."