Michelin Primacy 4 and Pirelli Powergy 195/55 R15 85V are available for your factory 15-inch fitment at Tyres.co.uk for the Ford Ka. The Ford Ka Active has 185/60 R15 84H instead, so check the registration and door-placard before ordering.
The adhesive placard, located on the driver's side door frame, shows the Ford Ka tyre information. On the frame, it displays approved tyre size, load index, speed rating, and cold pressure guidelines. Please check and confirm your specifications as tyre fitments can vary by trim.
You do not have to replace all four tyres on a Ford Ka. With Ford Ka being front wheel drive, there is no drive train version that requires all four tyres to be matched. Tyres should be matched by size, type, and performance on each axle. When two new tyres are fitted, British safety recommendations state that the new tyres should be fitted to the rear axle.