Indeed. Maybe they're testing the new brake cooling on the W11 and doing comparisons with the W16.
Sure, different tyres and rims etc but would be a worthwhile test. That being said, I am unsure of how much you can add new bits to old cars in that sense. I'd imagine the FIA would be all over that straight away.
IIRC the 2nd Honda PU in 2021 had a revised turbocharger, which was brought under the guise of reliability. That also came with a noticeable boost in performance, which is where the accusations arose from. From what I recall, there was speculation that Honda and RBR deliberately ran the first PU too hard to force the idea that a reliability change was needed. Indeed Max had warning messages on his dash regarding the PU quite famously in Bahrain.Alexf1 wrote: ↑11 May 2025, 09:472021 and 2022 say hello: Toto was all over the media about the supposed increase in HP of the 2nd Honda PU, publically threatening to take the FIA to International court of appeal about Red Bulls bending rear wing and pressured the FIA to stop Red Bulls fast pitstops. In 2022 he didn't want to change his cars rear suspension to stop it from porpoising and bounching but change the regulations. All these things he played very much via the media
So in that sense, the accusation appears to be they made a performance upgrade under the freeze, but used reliability as a means to get it sanctioned.