Team boss Eric Boullier has said that he is not worried about engine reliability for 2018.
After three bad years with Honda, McLaren have switched to customer Renault power for this year.
However, although Honda's reliability was woeful, Renault finished last season also notably struggling with technical problems.
Asked if that is a worry, Boullier told France's Auto Hebdo: "Not at all.
"Renault has taken the necessary measures and made great efforts to make progress in this area."
Boullier said that McLaren have also worked very hard over the winter on the Renault switch.
"The employees voluntarily worked throughout the holidays," the Frenchman revealed.
"Everyone has taken the news about the transition to Renault very positively, and we are working perfectly with our new supplier already."
However, it might be said that there is big pressure on McLaren this year, given their bold claims about their chassis and the fact Red Bull has won races with the Renault engine.
"We do not feel additional pressure," Boullier insisted. "On the contrary. The team is motivated by the fact that we will have two strong rivals in Red Bull and Renault.
"McLaren is in Formula 1 to perform, not for the numbers."
Finally, Boullier declined to confirm or deny McLaren executive Zak Brown's hint that the 2018 car may be painted in a full orange livery.
