Keep buying cheap tires...

[thstone]

The charts that I posted are not only valid for perfect conditions but also for the imperfect real world conditions that we all drive in daily. The compound of a tire (which is a big factor in how well it grips) makes a huge difference in stopping distance!

Then, you ask, why don't manufacturers sell cars with the most sticky tires if they stop shorter? As we have discussed before, tires are a trade-off. High grip typically comes at the expense of long wear, higher cost, and increased road noise, to name a few. The OEM tires are where the manufacturer felt the trade off's were best. Sometimes this means that a cheaper, quieter, longer lasting tire is selected.

But this doesn't change the fact that the cheaper, quieter, and longer lasting tire is more likely to take quite a bit longer to stop than a more expensive, louder, and short lasting stickier tire. Which was the OP's original point.

Again, choose wisely - or leave extra distance and plan well in advance!