[Rupert the bear]

When my mowing areas are improved, I might add a layer of more agressive tread to the drive wheels (strips of off-road cycle tyres ?) to ensure max' speed over ground in all conditions, but all is good right now.  I doubt this would need to be considered at all for domestic lawn situations.

I once spent a evening screwing football boot studs into a set of tyres for enhanced grip, and they worked well too !!