the other day i decided to try the new kumho xs on an itr swapped dc2. after ordering a set of 205 50 15s on those 12.8lb tr motorsport wheels i figured i would have a cheap combo for another set of wheels. personally, i've driven on quite a few different tires including the nitto 555R, NT01 yokohama es100, kumho mx, 712,ast, spt. BFG KD, KDW2, dunlop sport maxx, federal 595, michelin PS2, sport cup, falken 512, 615, toyo t1s, fz4 and probably a few others i'm forgetting {on various cars}.

to date the xs is the best non r compound tire i have driven. it's cold grip is really something else and beats my previous favorite, the discontinued BFG KD which i loved mainly because it was so predictable. what really surprised me about the xs is how quite and balanced it is. very smooth tire to drive on the freeway and quieter than the dunlop sport maxx which has a good deal less rubber on the ground. since i have a set of these laying around on a set of 17s i back to backed them. normally more rubber = more noise, not so with the xs.

this tire really amazes me and i don't say that often

 

How would you compare them to star spec z1?

 

There's a side-by-side comparison test on the Tire Rack website of the Kumho XS, the Dunlop Star Spec, the Bridgestone RE-11, and the Yokohama AD08. All four tires offered outstanding grip on dry pavement. The XS did not grip quite as well as the others on wet pavement, though. The XS and the Star Spec are usually less expensive than the other two.

 

both look great ill try dunlop first

 

have not done a side by side. i do know the xs is better than the last gen dunlop flag tire the sport maxx. from what others are saying the star spec and xs run almost identical times. for most of us the choice is more of "do i want 195 55 15 or 205 50 15" your choice determines which tire you get. the real hot one is that new hankook 3 that comes in 225 45 15. i'd really love to get my hands on a set of those

 

Those are two entirely different kinds of tires. The XS is an "extreme performance summer tire", designed for the maximum grip on dry pavement, period, with little regard to wet grip, treadlife, etc. The SP Sport Maxx is a "maximum performance summer tire", designed to grip well on dry pavement and in rain, and to last longer than tires like the XS and Star Spec.

Treadwidth doesn't make a whole lot of difference in performance. If you did a blind driving test between the same tires in two different sizes that are 10-20 mm different in width, it would be virtually impossible to tell which is which. Differences in design (compound, tread pattern, etc) are almost always way more significant than differences in treadwidth.

 

what again does this have to do with each only being available in one size? the star in 195, xs in 205 and H3 in 225 45

 

grass roots already did an article on this. the xs came out on top vs rt615, star spec, proxes r1r, re 01r, and re11. i also have a chart of the weights, diameter and tread width

 

exactly the article that made me buy the xs