Red Bull's 2018 Formula One season has been stop-start, to say the least.

Both Daniel Ricciardo and Max Verstappen have achieved podium finishes - but they've also had two races already where neither of them finished, the most ridiculous being in Baku where a collision between the Red Bull duo forced both into retirement.

Still, the good has been very good, with Ricciardo setting the fastest lap in all three races in which he did finish and winning in China.

The negatives haven't been totally put down to Red Bull, however, with the team almost universally blaming engine manufacturer Renault for any failings.

Adrian Newey described the situations as "we've got an engine which is quite a long way behind, with all sorts of failings, and with no obvious light at the end of the tunnel", while Helmut Marko said that Red Bull "need a fast and reliable engine" in order to compete.

The two teams have worked together for a long time, including a period where Red Bull won several championships, but the complaints began quickly this season as Christian Horner described Renault's engine as 'unacceptable' after the very first race of the season.

Understandably, Renault have taken offence to all the criticism and managing director Cyril Abiteboul has bitten back.

“Red Bull criticising its engine supplier is nothing new,” said Abiteboul. “We have been with them for 12 years, won eight championships together, and yet Renault is still criticised.

"We are used to it.

“They will never learn and they will never be able to appreciate the need for loyalty and commitment to a supplier.”

As for McLaren, Renault's other F1 customer, Abiteboul is a lot more positive, believing them to be a great reference for his team's work.

“If Red Bull is the aerodynamic reference, then McLaren is for the mechanical part of the car,” he said.

“It’s a great opportunity for us so we’ll see where it takes us, for now until 2020.

“We’ll see what happens then.”