Losing a full day of testing due to an engine problem hasn’t knocked Toro Rosso’s Franz Tost’s confidence in the Renault engine. The team is switching back to Renault power after running a Ferrari engine in 2016. It’s a move the team are happy with, despite losing a day’s worth of running and completing the least number of kilometres over the four days. “I’m convinced that Renault is around it, all these problems are nothing major and I’m quite optimistic that we will be very prepared for the second test and for the races,” said Tost. There will be a lot of Toro Rosso to do this week in the final running ahead of the first race of the championship. Though Tost said the team got a good amount of running throughout the first test, they are still missing some vital information, especially regarding the tyre compounds. Toro Rosso may be sure the problems aren’t big, but Renault haven’t yet given a reason for the issue. “I don’t think it’s installation related, from what we can tell,” said Technical Chief James Key. “Anything that’s happened on the power unit side we’ve had discussions on that, but they don’t appear to be to do with anything specific on our car.” For more thoughts on Formula One and the latest news, head to the Formula One sub forum here at RaceDepartment. Do you expect the Renault engine to be reliable this season? Was the switch from Ferrari a mistake or Toro Rosso? Let us know your thoughts in the comments below.