It is notable how the development of the Red Bull and Ferrari, comfortably the two fastest cars of the season, seems to be influenced by their relative strengths and weaknesses. The Red Bull RB18 has in general displayed a straight-line speed advantage over the Ferrari F1-75, which in-turn has usually shown a cornering advantage.
Both teams brought significant upgrades to Paul Ricard, both of which centred on changes to the tunnel inlets. The entries to the underbody tunnels are divided up by three regulation fences, which direct the flow either to the rear of the tunnel (via the inboard fences) or out-washing away from the car (via the outboard fences).
There is a balance to be struck between the two sets of flow. Both create downforce but in different ways, and with a different emphasis between the front to rear balance of the downforce.