Original Bridgestones changed at 26,000. These had a little life left, but had bad wear to inner edge on front tyres and were starting to crack.
Swapped for Michelin PS4S and fitted USRS bushes at the same time. Showing even wear after 16,000 miles. Front are about 1/2 worn, rears 2/3.
I would estimate 20K+ on rears, with 30K possible on fronts.