Review Of The Kumho Ecsta Ku31

[Bass Junky]

Spomething I read at Lunch.

Taken from the "Skoda Forum" (of all places !! )

Hi to All

Have just had fitted 4 Kumho KU31 tyres on standard Fabia vRS rims. Size is 205/45 R16 87W. First impressions are that they are a little quiter and less harsh than the Continental SCII were when new. Sidewalls seem stiffer than the Contis when new as well.

Looking at and prodding the sidewalls of the tyres before fitting, it is clear that they have a very small and firm (almost undetectable) comfort band in the sidewall. This compares favourably with the softer and around 3/8 inch comfort band on the SCII. Rim protection is not as deep as the Conti SCII. There is a lot more lug in the tread around the outer edges of the tyres as well. The void area looks to be greater than on the Contis. The compound feels softer than the Contis when cold and the tyres seem to build up heat and get working quickly.

Wearing a little of the mould release agent off the tyres, they are starting to "come in" after around 100 miles. Initial impressions are that the tyre needs a bigger slip angle to generate cornering force than the SCII, so more steering is required to get around a given corner. As a result, turn in feels subjectively slower, although once turned in, the tyres more rigid structure makes it feel more positive. This increased need for slip angle may just be a result of the tyres newness.

The tyres are still too new to start leaning on them heavily, but a quick go at hoiking it into a corner and loading the back up gave a fairly big sideways attitude through the corner, followed by excellent front end grip under power on the way out allowing the car to keep the back end loaded. On the downside, considerably more steering had to be used to do this than the SCII, so therefore, less optimal balance is achieved. I will give them another two or three hundred miles to scrub, which may well improve matters.

The stiffer sidewalls seem to suit the standard damping very well. The SCII sidewalls went from soft to baggy after 5000 miles and this made the tyres springy and seemingly bouncy. The KU31 seem to be much better in this respect and are better suited to the microdamping properties of the standard setup. Wheel patter over broken surfaces is hugely improved. The primary ride is also improved with the car / tyre system combining to feel better damped than it ever did with the SCIIs.

So far, so good. Will add to the review as the miles go on and as I get to try them in the wet.

Hard cornering and wet weather performance at 300 miles update

OK, 330 miles total mileage on the KU31 and it starts to chuck it down with rain. In the interests of science and for you lot, I went out for a little tyre testing tonight. Well I did expect to report that alas I got what I paid for (£53.95 each). However, it would seem I got considerably more than I paid for.

Dry performance:

The tyres have scrubbed in now and have settled down nicely. Turn in still requires more lock to be applied than the Conti SCIIs but once turned in, the tyres provide a stable and accurate response. Steering feel is pretty good and you are aware of the amount of grip you are using. The car does feel a little loose at the back end, but this is because the tyres take on a more sideways stance to corner than did the SCIIs. So when you turn in, it feels a little vague at the back. Lean on it a bit more, turn in a bit harder, get the back starting to swing and apply some gas to balance and the rears dig in nicely. You end up going a bit more sideways than is immediately comfortable in a FWD car, but as long as you have power left to drag it straight should the back start to let go, it all seems very "right". I would say that outright lateral grip is a little better than the SCIIs. Certainly, once loaded into the corner, the car is more resolutely stuck on its line where the Contis would have the car loading and unloading the rear end as the front bounced around, on these it just stays pinned.

Braking grip is another area where the Kumhos have a slight advantage. Doing emergency stops with a customer today, it was quite obvious that the ABS cuts in later on these tyres. Straight line traction is also improved over the SCII.

On higher speed corners, stability compares favourably with the SCIIs. The stiffer sidewalls inspire more confidence and you get more feel of road surface and camber changes.

Once the limit of adhesion is breached, the higher slip angles and speeds will make this car on these tyres a little less easy to catch than the SCIIs, but the rear end seems to let go first consitently and more gas seems to just haul it back into line. It is by no means snappy though and communicates its intentions well.

Wet performance:

In normal driving, the tyres give a very surefooted and positive feel. There is again plenty of feedback when turning and they feel good under braking and acceleration. Upping the pace to push on a bit harder, the stable feel stays. A trait carried over from the dry handling is the increased slip angle required to achieve turn in over the SCIIs. Again, this manifests itself as a feeling that the whole plot is going to go horribly sideways, but agian, lean on it more and the grip is there, just more sideways in attitude. Actual grip levels are definately higher than I have ever had with the SCIIs in the wet.

Once past the limit of adhesion, the tyres break away in a less progressive fashion than the SCIIs. Where the Contis would start to drift and rumble across the surface quite early on, the Kumhos are still digging in. However, once they do start to let go, you feel it more as an increase in the sideways stance. Again, applying gas sorts it out. Feel past the limit is a bit odd. You get a real sense of the tyres stick-slipping as if they are letting go and re gripping as the load comes off. It is pretty easy to modulate this and control the slide. Wet traction out of corners is ahead of the capabilities of the SCIIs when they were new. What is particualrly striking is the way the front pulls deeper into the corners when the throttle is applied, this I assume being the result of the bigger front end slip angle.

In the intersts of science, I put the car through a local spot where water runs off across the road. It was enough to see the Contis, when worn down to 3mm, aquaplaning at 80 ish (KPH officer). Same stretch tonight was comfortable at a little under 100 (KPH officer). Obviously the tyres are new and the Contis used to go through it nicely when they were new also. It does confirm that aquaplaning wont be an issue unless you are taking the p, which given the large void ratio of the KU31 is no surprise. Steering feel lets you know you are in the standing water more directly and more obviously.

Emergency stopping showed no problems and again, a high level of grip and plenty of info about the surface and camber changes coming back through the wheel.

850 miles tyres settled down

OK, so with 850 miles on them, the Kumho KU31 seem to have settled down. Above comments about ride and compatability with the standard Fabia vRS springing and damping still apply. Road noise seems to be transmitted less harshly than with the Contis, but on really smooth surfaces where the contis would be very quiet, the Kumhos are a little noisier. Having said that, to qualify the difference, I reduced the "gala" setting on the radio from 3 to 2.

The handling is still under question. There is a lot of grip for sure, more than the Contis, but and it is a significant but, when I steer with these fitted, I find that a lot of lock is needed to get the turn required. The downside of this is that the difference in slip angle front to rear is quite large, making it very difficult to get all four tyres working at optimum. It would seem that there are two ways to overcome this. One is to throw the car at the corner, get the rear swinging and nail the throttle to hold it all at the required angle. However, this is not really a subtle approach and relies on pushing the car into oversteer by trail braking or brutal steering. The second method is to turn in at the same sort of speed as would have suited the Contis, but then nial the gas and keep the lock applied. Curiously, this creates a ensation not unlike driving a FWD car with an LSD. The car seems to pull into the apex and if you are unsubtle enough, this unsettles the back and then re settles it once slip angle is achieved. Not pretty, but very fast. While I reckon that with practice these will prove to be the faster tyre on any given twisty road, the Contis actually gave better handling. It would appear that some handling has been sacrificed to get more grip / speed which is not an unusual trade off.

Progression is now very good wet or dry. They dont warn as early as the Contis, but then they dont let go as early as the Contis either. They do let go in a manageable way and do communicate what is going on.

Conclusion:

I have compared the Kumho KU31 to the Continental Sport Contact SCII, a tyre that came second to the Goodyear Eagle F1 GSD3 in an Evo tyre test. The Kumhos cost a whole lot of cash less than the Contis (£40 less per corner at the best price I could get for Contis) but the performance is if anything more suited to the Fabia standard setup. Dry grip is higher than the Conti on even surfaces and better still once bumps are introduced. Wet grip is again higher and steering feel improved. The tyres are generally a little less progressive, but with higher overall grip levels. This is always a tradeoff. The higher slip angle required for quick cornering may be of concern to some, but get used to it and the confidence grows. The key thing is that the stiffer structure allows you to use more of the grip and feel more of what is going on. So generally, these tyres out perform the Continental SCII in grip and feedback levels, but are not as good in terms of progression and handling.

The Kumho KU31 compound is evidently a fair bit softer than the SCII and I think this is where the performance advantage has come from, so wear wise, they will probably not be anywhere near as good as the Contis, however, my SCII sidewalls went baggy long before the tread wore out anyway.

So they are probably not the best tyre in the world, but they are extremely good, suit the Fabia setup very well and regardless of price, a recommendable product. Many thanks to those that helped my with the choosing.

Chris

[2rismo]

Damn... My last tyre review was about this long:

Falken ZE-326 - 235/45/17

Shit tyres in all conditions but smoke hard.

[dontfeelcold]

Those Falken's do smoke quite well

[BundyBear]

Car: R33 GTST (slightly above standard power) + Hicas

Driving style: kinda heavy 4 the street (no burnouts, just oversteer), no track ... yet

KU31'z on the back $245 each

Grip : 5/10 good 4 'normal' driving (wet or dry) slight second gear spin

Wear : dunno 3 weeks old

drift well, fairly 4giving BUT they HOWL like barstards as soon as you loose grip

Maxis MA-v1 on rear $225 each (6mths ago)

Grip: 5/10 Similar to the KU31z , a bit better straight line grip but a bit less in the corners ( & no howl). Give less grip while drifting than the Kumoz, so a little less 'confident'

Wear: 6/10 used 55-60% in 9 mths( on rear), now swaped 2 front

Maxis MA-v1 on front

Grip : 5/10 Grips fine, no understeer, However ABS seems 2 kick in kinda early ??

Wear : a lot slower now I suspect

Nankang somethings

Scary shit only good 4 burnouyts

0/10 ALL round

[stewari]

Nankang somethings

Scary shit only good 4 burnouyts

0/10 ALL round

that shit is gold

[Haxorz]

Some have reported the Kuhmo's are great back/buck but age quickly.

Any reports?

Right now I've narrowed it down to Bridgestones S001 at $400 a pop or Kuhmo's Ecsta KU?? at $270 or so.

[ARTZ]

i got 60,000kms out of ku31s on our honda accord....good tyre,,,they are running out stock cause its been superseeded by newer models, now so can get good prices on them

[dyl33]

I've been using them for about 5 months now. good tyre better then I thought they would be, and for the price I can't complain.

[GTSBoy]

Right now I've narrowed it down to Bridgestones S001 at $400 a pop or Kuhmo's Ecsta KU?? at $270 or so.

Those two tyres are in completely different segments. The Bridgey is a high end performance tyre. The KU31 is a budget brand, not particularly high performance tyre. I'm not slagging the KU31 off there, just pointing out the market segment it's aimed at.

When thinking about KU tyres, you might be confusing the KU31 with the KU36. The KU36 is a UHP tyre. Treadwear index is only 180. The longest I've ever had a set last is 15000km and they were probably rooted for the last 5000 of that. Driven hard I have killed a set in 5000km. They aren't perfect, but they do provide a lot of grip. Still a budget tyre by comparison to the Bridgey. The S001 will probably last 2-4 times longer than the KU36 whilst still providing a reasonably large fraction of the pure grip and working somewhat better in the wet.

[ARTZ]

What? a ku36 and a s0001 are not in the same league...Bridgestone is a street tyre, the ku36 is a race tyre..

Ku31 would be the Kumho equivelant of the s0001 or even a ku22.. and they last very well for the price

I'm sure a bridgestone is a better tyre , it would want to be for twice the price..but you will find a set of Kumhos much cheaper...

I wouldnt be paying more than 200$ a corner for kumhos..

I mean f**k if you are going to spend 400$ a tyre you may as well buy some Advans...

[GTSBoy]

KU36 is not a race tyre. They barely belong on the track. They are not even a semi. They're a semi semi. The point was that KU31 isn't really "equivalent" to S001 either and that some confusion as to what constitutes the "hot" Kumho may have been at play.

[ARTZ]

yeah, i see your point, i would of considered them a semi tho...lolz at semi semi...

[89CAL]

I've run KU31's a few times, Good tyre for street use. Couldnt complain at all about them. I have Yokohama's on the back now and the only real difference is they are a bit quieter

[niZmO_Man]

Google "tempe tyres" for better prices, especially for Kumhos.

KU31 is an excellent street tyre and I would buy it again (decided to try out other tyres). I'd say it's on par with Falken FK452 in terms of grip.

Longetivity, I had my KU31s last for over 20,000km, fronts were camber work but the rears went on for another 10,000km IIRC. Not bad on a heavy GT-R.

My old BNR34 wheels came with camber worn KU31s (approx 50%, unknown age), I drove around on them for about 10,000km and they were great, even in the wet. Had to change them because the insides were worn down to the belts hahaha.

[Dose Pipe Sutututu]

KU36 are good but will harden up and turn into a bucket of shit within a year and/or a few heat cycles.

Yes they're not a semi slick, for me anything with a tread wear above 100 is just an UHP tyre

[Blackkers]

I agree with the KU36's going off after a while. I had them on the dyno which is known to kill soft tyres, afterwards it was like I was iceskating for 4-5 days. Even locking rears into corners etc.

They came back to life eventually.

But with average cold performance, poor wet performance and extremely good warm performance they are too far gone for a street car and I would only recommend them as a 2nd set and NOT for daily.

Also if you're on the factory suspension don't dare go for tyres that sticky IMO. even on the track

Plus trying to skid on the 36's is ridiculous. you need decent power to do so and it just LAUNCHES you. I've skidded on crap tyres like everyone else but if you initiate a power slide on 36's you end up going too fast. too grippy, also much more difficult to save a slide in the dry. Mind you my car isn't set up to skid and if yours was, you wouldn't consider these tyres anyway.

in conclusion lol, don't bother dailying them

Edited June 1, 2014 by Blackkers

[GTSBoy]

I dailyed KU36s and I loved them. Apart from the noise and the short life that is. But the grip is addictive enough that going back to tyres that don't stick as well is depressing.

And I never had a problem with them in the wet unless they were stone cold. Always worked even in relatively deep water, although they could get up and aquaplane on a long enough stretch of it.

[GTRPSI]

KU31 turned to crap once half worn on our Honda S2000 however were good when new, im not a fan of them.

[Blackkers]

I dailyed KU36s and I loved them. Apart from the noise and the short life that is. But the grip is addictive enough that going back to tyres that don't stick as well is depressing.

And I never had a problem with them in the wet unless they were stone cold. Always worked even in relatively deep water, although they could get up and aquaplane on a long enough stretch of it.

How much air pressure did you use? Also what size of the tyre and what is your suspension set up?

[GTSBoy]

How much air pressure did you use? Also what size of the tyre and what is your suspension set up?

Typically 36-38 psi. R32 GTSt with stock arms, urethane camber bushes F&R, ball-end caster rods, sensible sporty street alignment, Bilstein@F & KYB@R + Kings springs, 24mm adjustable F&R. Spot on legal ride height.

Some of that has changed this month - new SK B6s F&R, GTR Kings Springs F&R. Not using KU36s atm having bought some Goodyears for almost nothing from Tirerack some months ago.

FWIW, the new dampers and springs have changed my car so much that I have more grip now on the lesser Goodyears than I did on KU36s, and if I were to put KU36s back on I would either have massive grip or I'd wear them out in 3 weeks (or both!).

Edited June 13, 2014 by GTSBoy