Circuit of The Americas
circuitoftheamericas.com
Harris Hill Raceway
harrishillroad.com
Kumho Tires
kumhotireusa.com
Tire Rack
tirerack.com
Yokohama Tire
yokohamatire.com
Photography Credit: Paul Flores | Mohflo Event Photography
Spoiler alert: Kumho has another worthy contender. The Korean tire manufacturer has long had a strong presence in the performance tire market, especially in amateur motorsports products. Its original Victoracer, introduced back in 1993, became the gold standard for pace, drivability, consistency and longevity.
Those characteristics held true through follow-up R-comp models like the Ecsta V700 and V710. And when 200tw tires fell into vogue, Kumho responded with the Ecsta XS, V720 and V720 ACR, a model specifically designed for the Viper ACR.
Kumho’s latest offering is the Ecsta V730, a modern 200tw model that borrows the tread design from the ACR tire and mates it to a new carcass.
After an early spring rollout in the minimum sizes needed for SCCA autocross and time trials eligibility, Kumho planned a more extensive portfolio for the early summer. Production and shipping delays due to the pandemic have unfortunately slowed progress on that effort. Still, we were able to snag a set of tires to fit one of our test mules, the One Lap CRX.
Our benchmark for the test would be our reigning champ on single-lap pace, the Yokohama Advan A052. In testing earlier this year, the Nankang CR-1 and Falken Azenis RT660 could only match the Yokohama’s pace when run in wider sizes than the Yokohama.
[200-treadwear tire test | Falken RT660 vs. Yokohama A052 vs. Nankang CR-1]
For this test, we’d run both tires in the ever-popular 205/50R15 size. As with many tires, however, the sizing marked on the sidewall is not always entirely reflective of its physical size. While the Tire and Rim Association regulates section width and overall diameters for a given marked size in the U.S. market, there is some wiggle room for effective tread width. Since that spec is not provided by manufacturers, Tire Rack has developed its own process for measuring it and includes the number in its listings.
Unfortunately, the 205/50R15 Kumho sits a bit narrow: a 7.0-inch tread width when measured on a 6.5-inch-wide wheel. On the same-sized wheel, the Yokohama’s tread measures 7.2 inches across, same as the Falken RT660. Where the Yokohama sits right at home on our Honda’s 9-inch-wide front wheels, the Kumhos looked a little stretched.
Test day at Harris Hill Raceway–just south of Austin, Texas– dawned in the low 80s, with temps climbing a bit during our 2-hour track time window. We mounted some scrubs and ran two short sessions to clean the track and get in the groove. Then we bolted on our fresh set of Yokohamas to lay down a baseline.
From left to right: Yokohama Advan A052, Kumho Ecsta V730. Photography Credit: Andy Hollis
One Lap of America Honda CRX. Photography Credit: Andy Hollis
Measurements on 6.5-inch wheel; prices and specs courtesy Tire Rack.
Best lap: 1:25.2
We have a love/hate relationship with this tire. It really delivers the goods on pace, but only for a short period before excess heat causes a drop-off. You’d better hit your marks quickly if you’re competing on these. Their vague steering response also adds to the challenge.
That said, the grip level is unmatched in the 200tw category, and the Yokohama delivers it over a wide range of slip angles. Combine that with a gradual breakaway, and the driver receives a massive performance window.
On the first circuit, we stopped the clocks at 1:25.8 before dropping to a 1:25.3 and then a 1:25.2. Each of those laps had a small bobble worth about 2 tenths, but the fourth lap was looking to be the flyer–until halfway through, when the tires finally overheated and grip fell off.
Best lap: 1:26.1
Once on the Kumhos, we immediately noticed a more authoritative steering characteristic that made it easier to drive the car down to the apex. Countering that, however, was a slightly lower grip threshold and a more sudden breakaway.
This peakiness made corner entry more difficult, as slip angle could not be used to help slow the car. Braking was also more challenging, since this car doesn’t have ABS to help keep tires right at the grip threshold. A deft touch was now needed on both the steering wheel and pedals. Altering our approach to suit the Kumho’s traits took a few laps. We first ran a 1:27.0 and then a pair of 1:26.6s before dropping to a duo of consistent 1:26.1 laps.
Impressively, grip levels never fell off. So while the tire requires some familiarity to extract maximum performance, it delivers it for entire sessions. Consistency is its forte, making it an ideal choice for lapping days and even mild endurance use.
Best lap: 1:24.8
To properly bracket our test and quantify any track and driver improvements, we bolted the Yokohamas back on for a final session. We quickly cracked off a series of 1:24.8 laps to back up our earlier efforts on this tire. While times were a bit quicker, the data logger revealed that the gains came entirely from a single lesson the driver learned: improved braking into Turn 10.
Our standard testing left us wanting to know more about the consistency and longevity of the new Kumho. Did we have an endurance tire on our hands?
So we ran the new Kumho at a Circuit of The Americas track day later that week, where it cracked off consistent laps–all within two-tenths–over a full session in 95-degree ambient temps. Impressive.
We also returned to Harris Hill Raceway the following week to play with air pressure based on the wear pattern the Kumhos were developing. Lowering hot pressures from 32 to 29 netted us more uniform tread use and a less peaky grip profile. Now that the tire was easier to drive, our lap times dropped another half a second. We also ran a dozen consistent laps in a row, with our quickest sprinkled throughout the session.
We really like the new Ecsta V730, as it does indeed live up to the traditional Kumho characteristics of drivability, consistency and longevity. While not the quickest on single- lap pace, it’s right in the mix and offers many chances at nailing great laps at any time in a session. Call it nearly as quick as the Falken Azenis RT660 and almost as consistent as the Hankook Ventus RS4–so, basically, it’s another worthy contender.
Further, the Kumho’s wide, semi-slick shoulder fights accelerated cornering wear, making it a strong choice for applications that are challenged by narrow wheel width or limited negative camber.
The cherry on top? The Kumho Ecsta V730 is the least expensive offering in today’s 200tw category.
Awesome! Great to read a review on the new Kumho. I used 720s on a Mustang project and thought they were a performance bargain.
I know you only have a handful of sessions on it, but any observations on wear vs. RS4?
Huh, on tirerack, for 225s they're higher than RT660s, and 205s same price.
Thought I might try them on my 8s if they were cheap enough.
i have dry, wet, autocross, and time attack videos along with a detailed review on my youtube channel for those who are interested. They are a good budget tire.
http://www.youtube.com/user/mchuffman
I ran a set of 205/50/15 V730 on a 99 Miata for one event on the other side of the state. This involved a ~500 mile round trip, plenty of autocross laps, on a camber challenged car, with a bit of fairly heavy rain in the mix on the highway. Car kept reasonable speeds on the highway in the rain, with no signs of hydroplaning.
Stuck this wheel / tire package on the Exocet (Project Princess Kart, I call it), and I have to say, I'm impressed. Even with a worn out Miata suspension underneath it, complete with blown rear shocks and original bushings from 2002, the car is dominant in local competition (big fish, small pond situation here, for sure), when we took it to Utah to shake it down with some faster folks, it did not disappoint. Managed something like 11th and 19th best raw times at their Octoberfast event.
The thing that impresses me the most about this tire is that it just doesn't seem to care about heat. Where the RE71R would eventually start to fade off on big sweepers, this tire just keeps on holding its line. That, and it seems to be wearing like stones. Easily over 300 runs between myself and a co-driver, plus that road trip to Cheyenne and back, and we finally wore off the outer groove on all four tires... barely. I can easily see this tire getting 500 runs on a light car.
In reply to te72 :
"...doesn't care about heat."
That's a major factor in my decision when I consider what choice of tires for my ES Miata. It's mostly had the Rival 1.5, and I like not needing to spray them between runs, and having them still maintain grip throughout the entire session.
In the 225/45-15 size, the Rivals are about $14 per tire more, or $56 a set, a nice savings if they're comparable in performance. The 205/50-15 is only about $149 per tire.
Just getting back into autocross after many years away, and will be introducing my 17yr old this year to it! He is sooo excited. We will be running a GS 2002 BMW 325i 5 speed with most of the limited upgrades and setup (shocks/struts @ B6s, larger front bar) we can do, and I think @ street we are limited to 16 or 17x7" wheels and tires. I have been trying to research tire options, and seems like this might be good choice for this first season, or RT660s? Just want him to learn and maybe competitive by end of season locally, and will be doing dual drivers, so want them to last the season and not overheat. Thoughts?
In reply to Matt Huffman :
I appreciated your V730 coverage and track review. Those contributed to my decision to purchase these for my 2022 autocross season with my new BRZ. Thanks!
Just bought a set of these for the Rabbit to use for streets as well as lower temp autox when the purple crack isn't optimal. Looking forward to them!
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