Toro Rosso team principal Franz Tost has admitted the team know very little about their 2014 car, the STR9, because of the limited running it has completed.
The Italian outfit, sister-team to Red Bull, has completed just 616 miles during the Jerez and Bahrain test, whilst the Mercedes team has done over 1,909 miles.
“It is difficult to assess the performance of the car,” he told SpeedWeek. “We hardly know how the car handles, because we have done so few laps.
“Both the reliability and performance represent two unknowns.”
He is however confident Renault is making some progress with the new power unit, but admits they’re well behind their rivals.
“In addition to the much nicer weather [in Bahrain], the power unit performed better. Renault has made progress,” he added.
“The Mercedes factory team is clearly in the lead, followed by McLaren and Ferrari. Williams and Force India also showed good performance. With Ferrari I have a feeling they are not showing their whole hand.”
Catching up with Mercedes by the season opener in Australia? Tost reckons it’s possible if things go well at the final test in Bahrain this week.
“The time to Melbourne is tight,” he said. “But if everything works at the second test in Bahrain, there is a real opportunity to catch up to the Mercedes team.”
