It does make a difference.
The numbers you refer to are the load rating for the tyre.
Basically the higher the number the more load the tyre can take.
82V are load rated at 475 kg and 149mph speed rated, whereas
81V are load rated at 462 kg and 149 mph speed rated.
You should buy exactly the same as the originals tyre's marking's not a tyre that rated less for obvious reasons.