Toro Rosso team principal Franz Tost has admitted their reliability is a "weak point", but is confident that they can overcome their minor issues.
The Red Bull junior team had a strong final day in Barcelona with Carlos Sainz Jr racking up 132 laps in the eye-catching STR12 and finishing P3 with a best time of 1:19.837.
However, only the beleaguered McLaren completed fewer laps than Toro Rosso throughout the eight days of testing and Todt is well aware that reliability is the area that they need to improve most.
"After completing the two pre-season tests here in Barcelona I can affirm that the STR12 is a fast and competitive car," said Todt.
"One weak point is the reliability, as we’ve had too many issues over these two weeks.
"On the positive side, I can say that this situation has improved compared to last week’s T01, but there has still been a few problems that have taken track time away from us this week.
"The good news is that we know what the issues are – nothing major – so I’m confident we can solve them all before getting to Australia thanks to all the valuable data we’ve collected here.
"Regarding our drivers, I have to say that both Carlos and Daniil have done a fantastic job every time they’ve jumped in the car and provided very useful feedback.
"Our engineers will now analyse all the data gathered to optimise the set-up for Melbourne.
"I’m really looking forward to the season ahead, I think we’re going to have a very interesting fight with the midfield teams and I just can’t wait to get started!"