Originally Posted by 72Tornado

Amazed the XS hasn't gotten more votes. My thoughts after extensive experience on both the Z1 and the Kumhos (basically a full autox season on each):

The XS is simply a fantastic tire and a phenomenal value for money to boot. That said, the Star Spec is also a very strong performer, and each has its own advantages and disadvantages.

What the Kumhos excel at - certainly beyond the Dunlops - is delivering incredible lateral grip. You can carry simply amazing speeds through all sorts of corners and the tires just grip. Their longitudinal grip does suffer, however, although that obviously isn't as much of a problem in our cars. They also lose a bit in terms of responsiveness compared to the Star Specs - the sidewalls is softer, making the tire feel less precise. When you turn in, you can feel a delay as the sidewall rolls, but then the tire just bites in and holds.

The Star Specs were great in their own right but lose some of the Kumhos' outstanding lateral grip in exchange for quicker, more agile responses. The Dunlops are also far, far better in the rain (and the cold), but this won't ever be an issue unless you're actually on track as it's raining.

Both tires are very predictable and progressive in their breakaway characteristics, making it easy to modulate them at the limit. I've noticed absolutely zero heat fade in the Kumhos, and maybe just a little in the Star Specs. Also, my set of Dunlops seemed to fall off as the tires got older, whereas the Kumhos seemed to stay at the same level.

I will warn that the XS is VERY soft and doesn't have anywhere near the longevity of the Star Specs. I was at around 2,000 miles and several events when my fronts were almost down to the wear bars (not to mention severely corded, but that was due to the toe out I was running).