Christian, have fun with it, it's your vehicle.
I used to run two sets of wheel/tires on my first D90, because I used it as a daily driver and actually wheeled that D90 during the warm months. I never went to a second set on the '97 because it rarely got off pavement and when it did, there wasn't much chance of damage.
Arthur M Vigil
Former owner of:
'95 RRC - 3.9V8 Rimmer Supercharged!
'72 Series III 88" NADA Turner 2.25 petrol (Lovely Rita)
'95 RRC Brooklands/TWR Edition 3.9V8
'97 D90SW NAS #2426 - 3.9V8 Rimmer Supercharged!
'95 D90ST NAS#2620 - Original owner