Renault believes that all is going according to plan with its engine development program so far in 2018.
The manufacturer prioritised reliability over power and performance for the opening rounds of the season. Despite issues with both Red Bull cars in Bahrain, Renault believes that the power unit is performing to expectations.
"Basically we wanted to confirm reliability, which we've done so far," Renault Sport boss Cyril Abiteboul told Motorsport.com.
"We have had an incident with Ricciardo," he admitted. "But the reason is still unknown, as we are talking.
"Whether it was chassis or engine related, we're still unsure of the root cause. It was an electrical issue, which obviously impacted the energy store," he added. ""Apart from that, ICE-wise and ERS, it's pretty okay."
Both Daniel Ricciardo retired in the opening laps of the Bahrain Grand Prix. While Ricciardo's issue was related to the energy store, Max Verstappen's demise was due to damage sustained in a collision with Lewis Hamilton.
However, Verstappen had reported an odd power surge on his car in qualifying the previous day, which Renault has investigated.
"The engine has done exactly what the throttle was asking," Abiteboul insisted. "It was very clear. It's a determinist thing - cause and consequence
"When you press on the throttle, something is happening to the engine," he explained. "The engine has reacted in exactly the same way that it was supposed to react."
With all cars from both the Renault works team and the McLaren customer squad going full distance in Australia and Bahrain, Abiteboul is confident that the company's reliability targets have been met.
That means he can now allow the teams to turn up the power and get more performance from the engines in China and the forthcoming European races.
"We are doing what we said we would be doing," he said. "We are obviously pushing the envelope in terms of usage and operation of the engine.
"It's starting to have some impact, in particular on a track like [Shanghai], which has a certain sensitivity to energy management."
Abiteboul added that both customer teams would receive the same level of hardware and support as the Renault team. "We are very transparent in that respect," he noted.
However with engines now having to last seven races to meet the three-units-per-season regulation, it will be some time before Renault are able to introduce technical upgrades.
"We'll have some more stuff coming from the ICE," he said. "And also with the fuel a bit later - depending on the teams, as we're not using the same fuel obviously.
"As far as hardware is concerned if we are sticking to our plan, it's for power unit number two, which is not coming for a while. For the time being it's more energy related."