McLaren explain key factors behind new Mercedes F1 engine delay

McLaren's Andrea Stella has detailed the reasons why the team is yet to take the new, reliability-improved Mercedes HPP F1 power unit. 

Over the Austrian GP weekend, Mercedes introduced new reliability fixes to its power units, with this on offer to customer teams Alpine, McLaren, and Williams. 

Whilst performance upgrades are not allowed outside of ADUO, which Mercedes has not yet taken, reliability upgrades are permitted throughout the season, with HPP deploying countermeasures to try and solve the issues which led to George Russell and Kimi Antonelli failing to finish the Canadian and Barcelona GPs, respectively.

McLaren has suffered from battery issues, including a double Did Not Start in China, but did not take the improved reliability on offer at the British GP - with Stella hinting that Lando Norris and Oscar Piastri could receive the new components next time out at the Belgian GP. 

Detailing the delay, Stella explained that one reason for it was that Alpine and Williams were "more in need" of receiving the fresh parts - including through Carlos Sainz, who took a whole new unit following the loss of one in his Austrian GP retirement. 

"We discussed with HPP the reason why we are not receiving this specification yet," Stella told media, including RacingNews365. 

"We understand the reasoning, we trust HPP, we've had such a great collaboration in previous years, and they've been totally instrumental in McLaren becoming world champions twice, so it is not changing the foundation of the relationship, and conversations remain ongoing.

"They are running fast, like we are running fast to develop our car, and they are running fast with four teams to supply, so there are some conditions whereby it was not possible ot supply the power unit to McLaren. 

"Hopefully, it is going to happen at the next event. 

"HPP, like any other team are in a process of development and fixing reliability issues. We have been affected by battery problems; others by ICE problems. They are all running as fast as they can, which means it is difficult for them to carry forward all the solutions and fixes.

"Even the allocation of power units is based on the mileage per car, because it looks like we are not on the latest specification, because Alpine and Williams have accrued more mileage than us, and they were more in need of upgrading their engine. 

"It is just the fact that everyone is working at maximum pace, and there are a few things that can be left behind, so we accept that this is part of the conversations we are having with HPP, who we have excellent relationships. 

 I think it's quite natural that, as a customer team, you remain a bit on the back foot."