hi
If you open the bonnet and find the chassis plate it will tell you the axle weights for your particular model , rear axle is normally a little higher . Divide by two and that's your requirement for each tyre .
The load rating is the last number usually followed by a "y" eg 275/40/20" 103 y , first numbers are the size last number load rating . A quick Google search will tell you what the number equates to in kgs .
Think we have 245/45/20" 106y so very capable on our T32.Hope this helps .