Toro Rosso desperately needs a step up in power, according to Carlos Sainz who found himself unable to get the measure of a Sauber running a year-old Ferrari engine in yesterday's Spanish GP.
While the Spanish driver was happy with his performance overall as he crossed the line seventh after starting P12, the speed deficit conceded to Pascal Wehrlein's Sauber in a straight line has showed the limits of Renault's current spec power unit.
"For the first time we were fighting the Sauber and it’s a bit of a desperate situation to have a Ferrari 2016 engine faster than us on the straights, compared to our car at the moment," Sainz lamented.
"I tried my best to pass him I was getting just enough to be side by side at turn 1, but he was covering the inside line of turn 1.
"It’s tough to pass here but he was doing a good job to cover the inside line where he could – so good on him."
Unfortunately, Renault has delayed the introduction of its revised engine - initially scheduled for Canada - indefinitely as the Viry engineers fine-tune its reliability.
"We need a bit more power," he told Autosport.com.
"We need that step and it’ll take probably another three races, so we need to be patient. We need to keep extracting what we have.
"In qualifying, we are not where we want to be, but in the race it is better and better.
"It’s been four consecutive races now where we try to fight back from a position in qualifying and I hope we don’t do this all year."