Newey says customer teams hit by restricted PU software.
Now is he right? Should manufacturers share their full engine software package, or is this one of F1s fundamental things - like constructing your own chassis - that differentiates each individual team?
MotoGP has gone totally open software, the 2016 rules forces all teams to run standard ECUs and all teams share from any resulting software development, no matter who suggests the improvement, as it's an open sharing system. However that seems like a mighty leap, never mind a step, to too far for F1 engine suppliers if it's translated in total to F1.
Adrian also says the fuel makes a contribution to the performance of the manufacturer teams, but I see that as a separate development avenue which any team can exploit already if they sign the right oil company.