We sell Michelin Primacy 5 and Continental PremiumContact 7 that are both 225/55 R17 and are perfect for C5 X7 Exclusive variants on the Citroen C5 at Tyres.co.uk. Please verify your Citroen C5's registration and check the tyre pressure label, as Citroen C5 fitments will vary with the year, with the trim, with the wheel option, with the load index, and with the speed rating.
For C5 details, look on the driver's side on the tyre/paint-code label. You can find the approved tyre sizes and pressures on the label on the door frame next to the driver's side door. Along with the registration, use the label to determine the correct replacement specification.
For Citroen C5 variants, it is not necessary to replace all four tyres. However, for all variants, the tyres on the same axle must be of the same type and construction. When replacing two tyres, the new tyres must be placed on the rear axle.