Toro Rosso team principal Franz Tost says the Faenza-based outfit experienced its best pre-season since its racing debut in 2006.
In the past two weeks, Max Verstappen and Carlos Sainz managed to complete a combined 1049 laps of the Circuit de Catalunya, making Toro Rosso the second most productive team after Mercedes.
This feat followed a hectic winter period due to a late decision on which engine to use in 2016.
The team worked on the development of the STR11 up to the very last moment, which resulted in the car running a temporary livery during the first week of testing.
"It was a positive surprise", Tost said. "To be honest, we didn't expect that we would be in a position to do so many laps after the last two, three months because we really had to work flat-out to finish the car in time."
"The first time I saw our gearbox and how it's fitted into the car, I said: ‘How on earth can we check the reliability?'
"You can't see all the cables and all the tubes anymore, because everything is covered. Fortunately it works so far, but we also have to prove it in the races. But at the moment I must say that from a reliability point of view I am quite happy."
"Up to now we had the best preparation as long as Toro Rosso exist", Tost continued. "Because we did so many laps and gathered so much data.
"From the driver point of the view, from the engineering side and also from a team perspective I think that we reached quite a good level."
"As you know, our target is to finish fifth in the constructors' championship and if we want to achieve this we have to perform well in all the races, we have to score points in all the races and sometimes, hopefully, also come up with a highlight, which would be a position in the first five."
Best case scenario
Technical director James Key was also surprised by how reliable the STR11 was running in Barcelona.
"Honestly, we didn't know how well the car would work coming here", Key admitted. "The priority was to make sure that 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 you normally do to prove various systems. We did our best and the numbers stacked up, but you never know until you hit the track."
"To hit the track and to do so many laps was a pleasant surprise, very much a best case scenario. We weren't expecting a disaster but we weren't expecting a 160 odd laps on most days either."
Additional reporting by Oleg Karpov and Jonathan Noble