Max Verstappen says his radio messages criticising the performance of his Renault power unit are intended to put pressure on the manufacturer to improve.

The Red Bull driver complained about his engine several times on the radio on Saturday in Shanghai.

He admitted his frustration with the situation when asked by RaceFans about his comments after qualifying.

“I think it would be a bad thing if it wouldn’t frustrate me, right?” said Verstappen. “I’m here to win races and I think everybody who’s working on my car wants exactly the same thing.

“If I would say it quietly I think I would be racing in GTs because I wouldn’t bother too much.”

Verstappen admitted his remarks were intended “to put a bit of pressure on them.

“Not only in public because what I say I don’t meant to the public, it’s to the guys who are listening to my radio.”

RaceFans believes Red Bull are forbidden from publicly criticising Renault’s power unit under the terms of their contract with the manufacturer. Red Bull’s engines are branded by sponsor TAG-Heuer.

Verstappen said he is still suffering from degradation in his power unit’s top speed when run at high revs, something he complained about last year.

“The gap on the straights were a bit bigger than we expected before we came here,” he said. “But then also from our side just fine-tuning [is needed].

“The power modes were not great. Some of the issues as well I’ve had before, like [getting] close to the limiter, some problems while upshifting and stuff, it just doesn’t really work.”

Verstappen’s radio messages

Final practice Verstappen On the exit I don’t know what the [censored by FOM]’s is going on there. What’s going on Max? Verstappen All the time when I push to the limit I’m just losing speed. I don’t want to do another fast lap. I’m not sure it’s healthy. I said this already last year in Baku about same kind of things happening now. Q3 Verstappen “Mate the engine again clipping in turn seven, [censored by FOM].

2018 F1 season