You know that to officially get the speed rating they run it for an hour at the target speed in a room heated to 100 degrees. I don't think I could even drive the damn car for an hour at 100 degrees without passing out.
Any of our tires that can still hold air are probably good for quick blasts to 140 or so, which is all you can really hit safely on the street anyway (not that it's safe to do that though
).