well, back in the 80s where F1 cars are turbocharged, the rear tires were huge. I wonder why colin chapman or adrian newey never experimented running their cars with smaller diameter tires to lower the moment of inertia.
Anyhow, though I understand the notion that smaller diameter tires will result lower lap times, I still wonder on whether it really makes a lot of difference considering foam donut weight is already very light in weight.