Current M4 Coupé tyres at Tyres.co.uk have options from Michelin and Pirelli with Pilot Sport 4 S and P Zero in size 275/35 ZR19 100Y XL for the front and 285/30 ZR20 99Y XL for the rear. Before finalising the purchase ensure the staggered sizes, loads and speeds as well as the XL specification are correct when compared against the registration.
You can find the BMW M4 tyre sizes on the placard close to the driver's side B-pillar when the door is open. This placard outlines the permitted tyre dimensions and pressure for the front and rear tyres. Check the sidewall and the handbook as well. Options available on the M4 vary so match the proper size.
There are no limits to M4 two tyres for the matched axle pair on the rear-wheel drive versions. However, in cases where the M4 xDrive Competition has been purchased, a matching fitment of tyres for both brands, designs and rolling circumferences is required. To satisfy this, all four must be changed. New tyres should be installed on the rear axle, in cases of only two new tyres purchased.