Toro Rosso says the mileage it accumulated in winter testing was the "best-case scenario" after the delay in securing an engine.
Toro Rosso only secured a switch to Ferrari power in December last year, with the team given permission to run year-old power units this season. In eight days of testing it completed 1049 laps at Barcelona's Circuit de Catalunya, second only to world champions Mercedes.
Technical chief James Key says the team was apprehensive coming into the winter and pleasantly surprised with how many laps it managed to complete following the "massive distraction" of waiting on an engine.
"We didn't know how good the car would be," Key admits. "The priority was to make sure we had a car ready to go in the best shape possible, but what kills you when you've got a very late decision is the lack of R&D to approve various systems. We did our best, and the numbers stacked up, but you never know until you hit the track.
"To do as many laps as we were able to do has been a pleasant surprise, very much a best-case scenario. We weren't expecting a disaster but I don't' think we were expecting 160-odd laps most days either."
Toro Rosso maintained an aggressive design to its current car despite the late decision on its power unit. The STR11's predecessor enjoyed its strongest qualifying performance in Barcelona, where it locked out the third row of the grid, and Key thinks the team has retained those strengths in its new car.
"It's obviously difficult to tell at this stage but it appears to. We wanted to improve on the strengths of last year's car and not lose the strengths, so we've kept the high-speed and medium-speed performance and attack the low-speed performance where we had a bit of a deficit, so hopefully we've kept hold of that. Certainly the evidence [from testing] suggests we've kept hold of that competitive high-speed performance."