Opinion Page:
There is no free lunch. I can weigh a car with a piece of paper, a pencil and a tire gauge. Contact patch is a function of PSI and weight, nothing more. However, narrow tires made a long flat area, which is bad for high speed.
Let's say you wildly overinflate drag tires to 100psi. The contact patch will be 1 sq in per 100lb. So if your front tire weighs 1000lb, it will make a pattern of 10 square inches. But it will be pretty flat sided.
AFAIK, there are no rules about running dangerously overloaded tires, it's up to the driver to figure that out. But that deflection will have it's consequences. As the tire speed rises, it will first make a second flat area, then a third, and so on until the whole circumference is a polygon. When the last two sides touch, the tire grenades. I really need to dig up those home movies when I get time. It's why we switched tires.
The good news is a front blowout normally handles a lot better. Bad news is at 100mph a tire becomes a deadly weapon when it grenades. If you don't have armor in the front, you could be killed. On just a street car at 55mph, I had the whole steel bed crumple like it was paper. That had to take several hundred lbs of force. People think someone hit me broadside at an intersection.
You could test it though. Standard Testing Labs (
http://www.stllabs.com/) is who I use to test tires. You will want to overload the tires, since you don't know if your car generates lift or downforce. I overload 20%. This is how you get videos of what happens.
If you are serious about pushing a tire past it's design limits, I'd test it first. It's a lot cheaper than testing on the freeway or a racetrack.
