@Graham be careful with tyre change. there are limits to what you can have side to side ad front/back.
From memory i think its 2mm difference in tread depth on the same axle and 3mm difference between the front and back axle or you risk transmission wind up at high speeds on the AWD system.
but please check this data as its only coming from what i can remember reading.
Il be buying 4 new Michelin crossclimates nearer winter. so will have some part worn good year suv's for sale.
Regards
Joe