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Confession time: We’ve been keeping secrets. It started innocently enough, with an email from a manufacturer asking us to find out how its new tire stacked up against the competition.
But this tire wasn’t yet available to the general public, and our testing would have to be confidential. Fair enough. We’ve been down this road before, sometimes with disappointing results.
This time, the results were much more encouraging. After several rounds of testing–and receiving confirmation that this tire is indeed heading to market–we have news to share. While it’s not a completely new tire–you’d be hard pressed to tell the difference visually–both the compound and internal structure have been changed. Hot spots have been eliminated by better distributing pressure across the tread face, while the rubber itself provides more grip while resisting overheating. In short, this revision has transformed the Nankang Sportnex CR-S from a finicky runner-up to a consistent front-runner.
Our development mule for this program is the Triple Threat ND Miata, which has seen thousands of laps around Harris Hill Raceway, our tire testing track. The Miata’s stock 180 horses are just enough to keep things interesting without getting into too much trouble should testing go awry. Pagid pads on OE Brembos give ample braking performance to sample a tire’s longitudinal capabilities. Most importantly, the car’s suspension is modified to provide proper camber for lateral grip evaluation.
However, we recently sourced some new wheels to replace the older, discontinued ones we’ve bent through various offs and curb strikes–yes, folks, full-send track testing on unknown tires is dangerous. To the rescue came Flyin’ Miata with a new private-label line called Kogeki. We sourced a set of strong and lightweight flow-formed wheels with perfect Miata fitments. They look especially aggressive in the 17×9-inch size wrapped in 245/40R17 rubber.
Our first round of testing was to compare the revised Nankang to the original. Each tire was first driven 40 miles to the track, given a six-lap scrub and heat cycle, driven home and then removed to cure. The street drives also allowed for some subjective analysis of road manners.
We performed the track testing using our standard process: a warmup session to clean the track and practice, then six or seven laps for each test tire. A final repeat session on the baseline tire bracketed the day to verify consistent track conditions and driver performance. Note that the baseline tire sessions are not shown here for brevity, but they bracketed well.
Nankang Sportnex CR-S (original)
- best lap: 1:27.15
- lap times: 1:27.27, 1:27.42, 1:27.15, 1:27.52, 1:27.85, 1:28.00, 1:28.04
► Highway: The CR-S has a soft feel to it and is fairly quiet for a 200tw street tire. Steering response is good, if not a little lazy. It has a very strong on-center feel promoting stability in road use.
► Track: The CR-S delivers strong grip but operates at large slip angles requiring significant steering input for cornering. Breakaway is very progressive with quick recovery, making the tire easy to drive at the limit. As heat builds with increasing lap count, grip and pace fall off and the tire becomes a bit sloppy to drive.
When we first track tested the original CR-S two years ago, it was on our front-drive One Lap CRX. We found that the tires overheated after just a couple of hard, sustained turns. On our better-balanced Miata, we got three good laps before falloff.
Nankang Sportnex CR-S (revised)
- best lap: 1:26.15
- lap times: 1:26.56, 1:26.15, 1:26.32, 1:26.35, 1:26.66, 1:26.52, 1:26.44
► Highway: The new CR-S–simply look for tire identification number on the sidewall ending in 23–retains the original’s soft, quiet highway feel but delivers steering response that’s much quicker and more athletic. On-center feel is lessened compared to the current CR-S, and the tire changes directions more easily. It does tend to tramline a bit, though, following undulations in the roadway.
► Track: The new CR-S delivers superior grip with improved response. The harder you push into a turn, the more it dives to the apex. Slip angles are smaller than with the current CR-S, yet breakaway is still progressive. Heat buildup slows later laps, but not nearly as much as with the other two tires. This is a delightful tire to drive.
Data analysis shows most of the time improvements came from a quicker pace in the two longest steady-state cornering areas as well as the corner exit acceleration zones thereafter. This is a result of superior grip and strong combined loading characteristics.
Photography Credit: Andy Hollis
So there you have it: The new CR-S is a full second faster and super consistent. The only potential downside is the need for some heat to get optimal grip. That might pose a challenge if you’re autocrossing on a cold morning, but it’s perfect for track days or the back-to-back runs of an SCCA ProSolo.
Round Two: Face-off against the current contenders
Of course, these results raise the question: Where does that full-second advantage put the new Nankang compared to the other 200tw top dogs? Glad you asked, especially since that top-dog list has recently been expanded to include the Bridgestone Potenza RE-71RS alongside the vaunted Yokohama Advan A052. Time to order some more tires, rinse and repeat.
With fall weather finally settling in, test day for round two was rather brisk. Overnight lows in the mid-40s kept the track surface cool even as the ambient temps rose to the mid-60s during testing. We took tire temps with a probe to see how each warmed up during the test. Test tires were kept stored inside our heated motorhome until mounted and run.
From left to right: Bridgestone Potenza RE-71RS, Nankang Sportnex CR-S, Yokohama Advan A052. Photography Credit: Andy Hollis
Nankang Sportnex CR-S (revised)
- best lap: 1:26.22
- size: 245/40R17
- weight: 25 lbs.
- price: $245
► Track: We were anxious to spend some more time with this tire, and it again delivered the goods. With the cooler temps, the out lap is a bit dicey, but by lap two it was mostly on point.
Looking closely at the data for the two quickest laps reveals that about two-tenths were left on the table by combining the best elements. Could it go even faster?
- lap times: 1:27.20, 1:26.24, 1:26.59, 1:26.42, 1:26.46, 1:26.32, 1:26.22
- tire temps: 70-133°F
- ambient temps: 54-56°F
Bridgestone Potenza RE-71RS
- best lap: 1:26.09
- size: 245/40R17
- weight: 23 lbs.
- price $237.19
► Highway: This tire displays a sharp steering response and runs at smaller slip angles. This gives it a more direct feel, with cornering loads building in a more linear fashion. While not particularly noisy for a 200tw tire, it does convey road irregularities more harshly than the others.
► Track: The RE-71RS comes up to temp fairly quickly and is quite consistent over a session. It’s especially good at combined loading events, trail-braking easily and putting power down early on corner exit.
The data says that the quickest lap had all the best segments of any of the laps.
- lap times: 1:26.29, 1:26.59, 1:26.09, 1:26.57, 1:26.42, 1:26.39
- tire temps: 71-143°F
- ambient temps: 57-59°F
Yokohama Advan A052
- best lap: 1:26.05
- size: 245/40R17
- weight: 22 lbs.
- price: $271.25
► Highway: The A052 delivers a soft feel, much like the CR-S. It does respond a bit quicker, but not as quickly as the RE-71RS.
► Track: The A052 works best cold, delivering its quickest times on the first two laps. However, heat builds rapidly with heavy loading, and grip falls off substantially. The tire then becomes rather challenging to drive at the limit. Laps three and four both included missteps as a result. Lap five is indicative of the heat-soaked level of grip.
Looking at the data for the two best laps reveals no more than a tenth would be gained in a theoretical best.
- lap times: 1:26.05, 1:26.09, 1:27.92, 1:27.51, 1:26.97
- tire temps: 71-141°F
- ambient temps: 61-62°F
Nankang Sportnex CR-S (revised) retest
► Track: Bracketing our test by rerunning the revised CR-S, we found a bit more pace. Further, the residual elevated core temps of the tires and the higher ambient temps allowed for more immediate compound activation compared to the earlier session.
Looking at the data, the two 1:25.7 laps are very similar–no more than a tenth would be gained by combining the best elements. This speaks well for the tire’s consistency and drivability.
Compared to the earlier morning laps on this tire, most of the time delta comes mid-corner in Turn 5–nearby construction leaves this turn dirty every morning, so the gains here likely came from additional track evolution and cleanup. The localized improvement begins with the RE-71RS session and stabilizes thereafter. Given that, this final session is more indicative of the revised Nankang’s pace than the first one.
- lap times: 1:26.65, 1:26.03, 1:25.78, 1:26.15, 1:25.72, 1:26.23, 1:26.30
- tire temps: 95-143°F
- ambient temps: 62-63°F
A new front-runner in the 200tw tire wars?
The stopwatch says that the revised Nankang is fast–as fast as anything else in the 200tw class. What else?
As the launch date for the revised tire approached, Nankang dropped a bombshell on us: an expanded sizing lineup. The company is so confident in the tire that it has invested in new molds to double the range with 21 new sizes.
These new sizes include the 255/35R20 and 315/30R21 for the Porsche 992 GT3, the 275/35R19 and 285/30R20 for the new BMW 3 and 4 Series, and other larger sizes like 335/30R18 and 325/30R19. The range starts with three 15-inch sizes, too: 195/50R15, 205/50R15 and 225/45R15.
With Nankang’s latest offering, 2023 looks to be a great year for motorsports tires at the grassroots level. The market offers something for everyone in terms of pace, consistency, durability and sizing.