Daniel Ricciardo expects Renault to be lacking some performance at the Spanish Grand Prix as it has used the three-week break since Bahrain to focus on stretching out mileage on its power units to delay engine penalties.
Ricciardo's engine failed spectacularly as he crossed the finish line in Bahrain, meaning he starts the fifth race of the year on his fourth power unit. Drivers are allowed four power units a season before incurring penalties, making them inevitable for the likes of Ricciardo.
The Australian says Renault's attempts to stretch out his engine life means he may be lacking the performance he could have had from the new power unit otherwise.
"I think for now the performance side is probably not going full steam ahead because of the reliability issues," Ricciardo said. "I think the main stuff we're trying to resolve this weekend is reliability. With the fourth engine we want to try and get this as far as it can go. Let's say that extra half tenth of performance we're going to put aside until we're 100% sure with what's happening with reliability.
"The plan is we have the fourth [engine] this weekend, and we would like to do here and Monaco and then after Monaco we need to assess the programme. Hopefully we can do the next few races but we have to look at the moment short term, here and Monaco is a priority for us."
Despite the focus on reliability Ricciardo does not think Red Bull will need to turn their engines down during the crucial sessions in Barcelona.
"I think when we have to run it during the practice sessions I'm sure we'll minimise the high-performance running and minimise the risk in general. But in the race we'll use the maximum we can. If something happens then it's a risk we need to take because we can't afford to compromise quali, that's for sure."
Even though he expects limitations from Renault Ricciardo is optimistic about the upgrades Red Bull has brought to Spain.
"I don't want to get too excited but I think this weekend has the potential to really put us back in that fight, at least with Williams, and get us closer to Ferrari. On paper, the aero gains we should make, should definitely put us closer. Like always it depends on what the other guys have done. But curing some of the balance issues and stuff we've had, these upgrades sound promising. I have a positive feeling."