If I understand correctly it is the depth of the tread. The CrossClimate uses a summer tyre trad depth. Probably the compound is a fraction harder than the snow tyres. I think this probably means that they will lose grip in the snow when they become somewhat consumed. I would change them a 5 years old regardless of wear.
I have been contemplating Cross Climates when I come to renew my tyres this year very happy with them on my Volvo and am now encouraged by your Morgan experience. Would be interested to know whether your fuel consumption has been affected, particularly when touring.
