What about Kumho XS Tires?

Alley

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I'm pretty happy with my tires I got. But at 3k miles, there pretty beat up. I got Kumho Ecsta V700s. So even though I got tread, with all the heat cycles they've been put through I'm worried the compound is now just getting harder and harder and my traction will suffer. The tread rating is 50 which is nice and soft.

I don't really wanna go with a street tire like the Michilline PS2's. 220 tread rating is a little hard for me.

These Kumho XS's seem to be almost middle of the road. Tread rating is 180. And there not classified as as competition tires, just ultra high performance summer tires. But are made for track and street use. Here's the right up.

The Ecsta XS (eXtreme Street) is Kumho’s Extreme Performance Summer tire developed for passionate driving enthusiasts looking to make the most of their vehicle’s capabilities in competition, at the track or on the street. The Ecsta XS is designed to deliver Kumho's ultimate level of dry road performance while maintaining wet traction. Like all summer tires, the Ecsta XS is not intended to be driven in near-freezing temperatures, through snow or on ice.

The Ecsta XS molds Kumho's high-grip synthetic resin enhanced tread compound into an asymmetric pattern that features wide outboard shoulders to deliver dry road responsiveness and cornering, along with a continuous center rib that offers linear handling and high-speed stability. Two wide circumferential center grooves and an inboard network of aggressive lateral aqua grooves enhance wet capability. The tire's structure includes two high-tensile steel belts reinforced by spirally wound nylon to provide excellent strength, uniform ride quality and high-speed capability while the sidewalls are tuned to resist lateral deflection and to provide handling control and positive feedback.

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You think I'd be happy with these for street driving and a 1/4 drag use? I know they won't be as good as the V700s. But I'm willing to sacrifice a little to get more life out of them, and there cheaper then the V700s and PS2s.
 

RedEnuf93

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except the largest they make in 18" is 315....(no 335's)
and only 275 for front.... (no 285's)
No go for me.

(They DO have the 17" sizes though.)
 

ACRBruce

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I have an '08 ACR and am thinking of getting these tires also. I spoke to the Kumho rep at SEMA about these tires and was told that these tires were rates at 180 becasuse it has to meet certain SCCA street tire class of competition and the actual compound is much softer than 180. I also did a non-so-scientific finger nail test on the tire and found it not much harder than the V700 which I'm also running on a Lotus. I'm thinking of going 315 fronts though with aftermarket wheels in 11" widths. Does anyone know if 315's would rub on a GenIV that's lowered to 105MM ride height?
 

treesnake

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I have an '08 ACR and am thinking of getting these tires also. I spoke to the Kumho rep at SEMA about these tires and was told that these tires were rates at 180 becasuse it has to meet certain SCCA street tire class of competition and the actual compound is much softer than 180. I also did a non-so-scientific finger nail test on the tire and found it not much harder than the V700 which I'm also running on a Lotus. I'm thinking of going 315 fronts though with aftermarket wheels in 11" widths. Does anyone know if 315's would rub on a GenIV that's lowered to 105MM ride height?

Just curious, what are you going to put on the back if 315-18 is the largest they make? Luke said the 335 is a "maybe" but it is still an 18?
 
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The XS tires for everyones info are HUGE!!! compared to the Sport Cups the actual contact patch is 1 and 5/8" wider in the rear! About 1" in the front so about the same as the 295 on the ACR.

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:headbang::headbang::headbang::drive:
 

ACRBruce

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The XS tires for everyones info are HUGE!!! compared to the Sport Cups the actual contact patch is 1 and 5/8" wider in the rear! About 1" in the front so about the same as the 295 on the ACR.
:headbang::headbang::headbang::drive:

Mark,
The rear tire fill out the rim perfectly, and the fronts are "only" 275's? So I guess the 315's might just be too wide? Also, how does the tire ride as compared to the PSC and Kumho's own V700? I find the V700 rides better than the PSC.
 
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Mark,
The rear tire fill out the rim perfectly, and the fronts are "only" 275's? So I guess the 315's might just be too wide? Also, how does the tire ride as compared to the PSC and Kumho's own V700? I find the V700 rides better than the PSC.


The little bit I have been able to drive I think the ride is on par with either one. Most Kumho tires ride well IMHO.
 

j-rho

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I have an '08 ACR and am thinking of getting these tires also. I spoke to the Kumho rep at SEMA about these tires and was told that these tires were rates at 180 becasuse it has to meet certain SCCA street tire class of competition and the actual compound is much softer than 180. I also did a non-so-scientific finger nail test on the tire and found it not much harder than the V700 which I'm also running on a Lotus. I'm thinking of going 315 fronts though with aftermarket wheels in 11" widths. Does anyone know if 315's would rub on a GenIV that's lowered to 105MM ride height?
Bruce, the XS is a great street tire, but it is not going to be as fast as a Michelin PSC on track. Its peers are tires like the Bridgestone RE01R, Yokohama Advan Neova AD07, Toyo T1R. It's in the top tier of street tires, which are still a half-step below something like the PSC or Victoracer, which themselves are slower than a V710 or A6/R6. If ultimate speed is not the concern, would be a great street tire choice.
 

JonB

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.....Bruce, the XS is a great street tire, but it is not going to be as fast as a Michelin PSC on track. Its peers are tires like the Bridgestone RE01R, Yokohama Advan Neova AD07, Toyo T1R. It's in the top tier of street tires, which are still a half-step below something like the PSC or Victoracer, which themselves are slower than a V710 or A6/R6. If ultimate speed is not the concern, would be a great street tire choice.....


I added the BOLD and I concur 100% , but noting that those other brads may / are not all available in Viper sizes
 

rcl4668

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Question for those who already have some real world experience with the new Kumhos: If one could have two sets of stock sized Viper rims, Set A for pure street driving and wet/cold track days and Set B for warmer weather dry track days, which would be better all around for wheel set Set A for colder/wet track performance, the OEM Michelin Pilot Sport PS2 or the new Kumho Ecsta XS? Thanks for your feedback.

/Rich
 

Big Mac

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I was told the XS's would be more likely to "fling up" debris, rocks, etc that would damage the paint vs. the PS2's. Has anyone experienced this? Got pics?
 

gb66gth

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I just want to know about putting the 315 on a stock gen IV front rim. Will it fit and will it rub against the inner wheel well?
 
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I was told the XS's would be more likely to "fling up" debris, rocks, etc that would damage the paint vs. the PS2's. Has anyone experienced this? Got pics?

Yes anytime you have a sticky compounded tire it will grab a hold of the rocks and do a little more damage. Clear bra will fix that though.
 
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I just want to know about putting the 315 on a stock gen IV front rim. Will it fit and will it rub against the inner wheel well?

It will fit but it will not be optimized on a 10" rim so I think it is a mute point even though a lot of people on here think it is a good fit. The turn in crispness will be less than a proper size on the rim. The ACR came with a 295 for this very reason.
 

JonB

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Question for those who already have some real world experience with the new Kumhos: If one could have two sets of stock sized Viper rims, Set A for pure street driving and wet/cold track days and Set B for warmer weather dry track days, which would be better all around for wheel set Set A for colder/wet track performance, the OEM Michelin Pilot Sport PS2 or the new Kumho Ecsta XS? Thanks for your feedback. /Rich

Rich.....anyone who claims VIPER experience on nthe XS is blowing smoke! They have only been out in rear sizes for 2 weeks....

THAT SAID: In the wet/cold, the XS cannot possibly be a better tire than the PS2. We have hard-data, lots of anexdotes at 90mph+ in raging rain......

The new XS has some similiarities tho: Assymetric, and sticky-grippy shoulders. But $400 less per set!
 

ACRBruce

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I just ordered a set of XS to replace my Nitto NT-01's for my Mitsubishi EVO X so I'll able to compare these two tires soon. In my books, the NT-01's w/ a 100 treadwear rating is very close to the PSC as I ran these two tires on two different cars that I owned for over a year. The NT-01's heats up a little faster while the PSC handled heat better, I can't comment on the wear as one car was front drive, the other was a mid-engine rear drive and much lighter (Ferrari Challenge Stradale.)
 

HensleySRT-10

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Ordered mine from Jon B. @ PartsRack. I have them but haven't gotten a chance to install them as of yet. They look amazing though!!!!!:headbang: I'm not in quite the ideal operating climate (Kentucky) but I will post a review when/if we get a warm day after the install.
 
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It's going to be 55 here tomorrow and I will be trying to put 300-500 miles on mine to do the break in. I hope to head south and get even warmer temps and will try and report my thoughts also on these tires. I have had them on the car now for about 18 days...
 

Leslie

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The XS's are WAY better that the MX's, the carcass is more in line with the 710's so turn in and grip stability is much improved over the MX.

awsome thanks! I have gone thru 5 sets of the Ecsta MX's (roadracing), have Nitto 555RII's on now and I went thru a tire in 2 days:lmao:...soooo looking for a bit higher tread wear rating
 
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awsome thanks! I have gone thru 5 sets of the Ecsta MX's (roadracing), have Nitto 555RII's on now and I went thru a tire in 2 days:lmao:...soooo looking for a bit higher tread wear rating


Tread wear is not always the reason for ruined tires. Track oriented tires have a much better carcass and the load is more evenly distributed, preventing the outside edge from being ruined quickly.
 

Leslie

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Tread wear is not always the reason for ruined tires. Track oriented tires have a much better carcass and the load is more evenly distributed, preventing the outside edge from being ruined quickly.

that makes sense. it was at Mid OH, front left tire...car was pushing a lot and I am ******* front tires at that track.
 

johnk

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Mark, what's your take on straight line traction? Think these offer a significant advantage over the PS2's on my Paxton car? Over the PSC's? They're really that much bigger? the specs look about the same.. ??

Thanks!
John
 
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Mark, what's your take on straight line traction? Think these offer a significant advantage over the PS2's on my Paxton car? Over the PSC's? They're really that much bigger? the specs look about the same.. ??

Thanks!
John

John,

I'm leaving now and will drive into 68 degree weather. I will post my thoughts this evening after 4-500 miles on them.
 

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