Carlos Sainz has backed Renault's efforts to improve the reliability of its power unit.
Renault, supplying engines not just to its own works team but also customer McLaren, has taken a big step forward with its 2019 unit.
But works driver Nico Hulkenberg, for instance, had to have not just his combustion engine but also the turbo and MGU-H replaced after Bahrain.
Asked if it's a "bad symptom" of the performance leap for 2019, McLaren driver Sainz said: "It's a bad symptom, that's right, but we have to congratulate Renault on the performance jump.
"We have three or four extra tenths compared to last year and that's very much appreciated," he told AS newspaper.
"But if you don't finish the race, more performance does you no good so hopefully they'll solve the reliability problems soon and we can start to take advantage of the extra horses," Sainz added.
The Spaniard admits that the advantage compared to last year's Renault is about 10kph on the straight.
"Yes, I was tired of competing in F1 with a car that was 10 or 12kph down on the straight and always defending or trying not to be overtaken," said Sainz.
"Although it has cost us a little reliability, I prefer more power and top speed but a team like Renault should be trying to achieve both."