In a WRC season, manufacturers can use only 3 engines per car. Actually one more if they request for it and have a good reason (which I think they will all have), so 4 engines per car per season. There's a similar rule regarding gearbox and diffs. Now my question is, does Citroën ("PH Sport") have to comply to these rules? Since they're not registered as a manufacturer, I think they don't. How much advantage can Citroën get from being able to have a new/different engine/gearbox etc every event? Maybe this could explain the fact that Citroën is more competitive this year on the events they're doing. Maybe someone on this forum who has more insight on the technical side of the sport can give us an explanation?