Not really sure what you are talking about, every year since 2014 the engine and cooling packaging has played a factor in car performance. Every year people are looking out for who has the neatest packaging. I don't see that changing, especially when you have a smaller form factor car to put it all in. Being the one who decides where to put the weight and volume is an advantage. Also setting the cooling requirements and being the one who tests the cooling first hand.FittingMechanics wrote: ↑27 Dec 2025, 11:53I believe this factory advantage is overblown. This is the age of engines that are much smaller than the bodywork that covers them, most of engines have plenty of room under the cover and the bodywork is used to help with the aero. This is not the age when the engines were big so if you wanted to pursue a certain aero direction you needed to adapt the engine to it.Badger wrote: ↑26 Dec 2025, 16:48HPP can design one engine that gives full factory benefits to two different teams? How does one serve two masters?Fred wrote: ↑24 Dec 2025, 01:33McLaren isn’t really a customer team and won’t have an higher risk of issues with the aero integration. They have an exclusive deal that allows them to be involved with and influence the engine design. It’s the exact same treatment the Mercedes factory team gets, so by all intents and purposes they are a factory team. Mercedes (or any other factory team) doesn’t have any additional advantages over them on this front.
As long as Mercedes has a factory team in the sport HPP's purpose will be to win with that team.
McLaren may have to accept general layout of Mercedes engine but this is not the penalty it used to be. McLaren also build their own gearbox and suspensions so they have more freedom than if they just accepted Mercedes built ones.
I guess we will see, but I just don't think it is a factor it used to be.
In addition, 2026 cars were not supposed to have been developed earlier than mid 2025. So legally, Mercedes couldn't really push their engine department toward a specific aero design they have. Even if they did, they couldn't have large amount of data to base this on as they couldn't run simulations or use wind tunnels for 2026 cars before that moment (and engines need more time than that to design). So 2026 should be even less of an advantage for Mercedes as they probably started to work on the car on the same day as McLaren and they both got the packaging information at that time.
My thoughts on the matter (I am a McLaren fan so not objective) is that it seems that McLaren realized their advantage very early on and predicted an easy WDC/WCC for McLaren, they switched development as early as possible to 2026. If true this is a plus for McLaren. Their correlation in last 3 years was perfect, all updates worked well and the car was improving faster than most other cars. If this holds, this is another good point for 2026.
But it's always hard to stay at the top. Realistically speaking someone else will probably get there, it could easily be Mercedes or Ferrari. Red Bull I would be surprised if they stay at the top, I think they sacrificed 2026 development to keep Max happy and to win political games, engine is a big question mark, their correlation wasn't very good and they struggled to understand their car. This makes me feel it's unlikely they get it right in 2026.
And the physical integration is only one aspect, there's also the software side. Driveability will be more important than ever with these PUs so seamless integration between your engine, chassi, and driver is bound to count for something on track. Customers are not completely out of the loop in this regard but they aren’t in full control either.
2026 cars began development on Jan 1 2025... officially. But we don't seriously think that HPP, RBPT, Ferrari were all designing their engines in a vacuum with no input from the chassi side until 12 months ago? That would be quite naive to believe IMO. You can't exactly prevent people from meeting and talking, even if it's "informal" officially. Their interests are aligned.

