Toro Rosso have opted to use Honda engines in this campaign, despite their reliability being questioned during their ill-fated three-year association with McLaren.
But Red Bull’s sister team completed the most laps during the first phase of pre-season testing while McLaren – now powered by Renault – have been hit by problems.
Toro Rosso boss Franz Tost said: ”We are happy with the Honda engine which is doing a fantastic job.
“I am convinced they will supply us with a very competitive package.
“I am sure that during the season we will catch up and by the end of the season we will have a very competitive car.
“Our target is to be in the front part of the midfield.
“I don’t care about McLaren. I am convinced that by the end we will have a more competitive package than them.”
McLaren’s MCL33 car broke down three times on the first day of the second and final block of tests yesterday.
Stoffel Vandoorne was twice hit by electrical problems in the morning before a technical issue ended his day’s work after lunch.
McLaren racing director Eric Boullier said: ”There is absolutely no drama.
“This is just testing. We push the car to the limits and we try some various conditions and set-ups and things. Sometimes it works, sometimes it doesn’t.
“The cars are complicated and when you have to change something in the heart of the car it takes longer than in the old days when it was much simpler.”
McLaren suffered a fresh setback this morning when Fernando Alonso was forced to stop his car.
The team have downplayed fears of a problem with their Renault engines, claiming Alonso was affected by an oil leak.