100tw Nankang AR-1, 245/40/15
 

Available outside the US as 80tw already. Coming to the US as 100tw, "soon" according to Nankang Motorsports. Probably through R Compound USA, at least. I know nothing else about their dealer network or anything. Their size chart doesn't even list the 225/45 or 245/40, but they're showing up on cars in EU and being tested here in socal.

https://cimg7.ibsrv.net/gimg/www.mia...606adc7eda.jpg
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These look very interesting. I actually ran one of the first batch of AR1s back at the start of 2016 in 195/50R15 on a 7J with the Supermiata race alignment settings. Were ridiculous as stickers, good for the next 10 or so heat cycles then became increasingly difficult to switch on. In the end, I couldn't kill them and removed them just due to the heat cycles but all still had more than 2mm tread all over. To replace them I went with AD08Rs in the same size, seemingly the stock engine heavy NB2 didn't have enough power (especially torque) to maintain slip angles with the AR1s and I prefer that car with the lower grip AD08Rs. Slight aside, but they had comedy levels of low grip in low temps with a few heat cycles when driving from the track but fine when new.

I also tried them in 225/40R18 on an 8J on a standard Renault Megane R26 (ie almost no camber, 230hp, 1350kg FWD car with LSD). Here they were very disappointing, barely any more grip than Michelin Pilot Super Sports and an axial tread split formed on day one, though never seemed to be an issue. The pyrometer readings obviously had the wrong gradient due to barely any camber, but they weren't as bad as the grip levels suggested.

I bought another set of 205/50R15 at the start of last year to run on 8s on my turbo track miata, but the 225/45R15 and 245/40R15 came out before I finished building the car so I bought some 9s. In the end, the huge European cost of these meant I bought a set of 225/45R15 Federal RS-RR and was very disappointed in the grip, so will likely replace with AR1s shortly.

Pro Track Wheels has fitment photos of these mounted on various rim widths on Instagram. It looks like 225/45R15 has a fair amount of stretch on a 9J. The quoted section width of the 225s isn't much more than the 205s, but the 245s are relatively fatter according to the sheet. (205 says 214mm, 225 says 225mm, 245 says 248mm). Also, oddly the 245 is lighter than even the 205.

One point to mention on the tread wear ratings, I highly suspect this has been driven by EU rolling resistance legislation eg 205/50R15 80TW = F for rolling resistance, 100TW = E. The EU are phasing out F rated tyres....

My experience is slightly different, bought some 195 AR-1 last October. Sidewalls are very stiff so they work just fine with super low pressures on stock 6J wheels, should be great on wider wheels. I ran them on the street for around 1000km including some 500km road trip (cold and rain), and a few mountain visits at high pace (so maybe 3-4 low intensity heat cycles). They heat decently fast after 5-6 hard corners and I ran them nicely at 1.9 bar with no issues due to the stiff sidewalls (even at 1.6bar they dont fold the sidewall that much so its definitely very nice).

After this, In December, trackday at Algarve circuit running -2.8f, -2.5r camber with stock NBFL sways, grip was very good. At the very end of the second 20m session I noticed the rear was a bit more loose. In the third session I confirmed the tires were significantly more buttery. Overall grip was still high but nowhere near the same feeling. That being said, the tires became a lot more fun at that point :)
I used over 50% of the tread during the 6x 20 minute sessions (4 with passenger), it is now maybe 3mm from the wear marks on the insides.

After the trackday, when cold (12-16 degrees C) the tires just have hilarious slip angle and low grip, similar to what Tran said. the first few km the car feels to me what I think driving those Goodwood classics on vintage tires feels like :P
After they warm up in the mountains the grip is definitely not terrible, but the feeling is very vague. (It is currently about 8C outside at night so you cant get them THAT hot)

TL;DR:
- They wear decently in terms of tread (I guess it should usually match the normal heat cycles anyway)
- They heat cycle very fast
- They heat up decently quickly even during "cold" weather (18C-21C ambient, 15-27C track)
- They are very loud and droney on the road
- They have good/stiff sidewalls so you can run very low pressures on thin wheels

Some other people here have ran them on faster turbo miatas with 225 size, from what I understand everyone kinda agrees that they appear to have similar grip to R888R, seem to warm up a bit faster but also seem to overheat easier.

Some people have 245s ready to go but have not tested yet. (its basically the only 245 option over here under 200 euro)

Hi,
just for comparison. AR-1 225/45 R15 on 15x9 6UL and Avon ZZR 205/50 R15 on Kosei K1 15x7.
Haven't tested on track yet.

https://cimg8.ibsrv.net/gimg/www.mia...d70b8b0351.jpg

Small update. After another trackday (Estoril), tread wear is much reduced and are still legal to drive on (even the left front (CW tracks)).
I think what nashvill said is accurate, as you heat cycle them they will become increasingly hard to kill.
That being said they can barely reach 1.1G sustained on a 1100kg NB at basically any speed, and the slip angle is hilarious (but very smooth and telegraphed at least). Highest peak G was usually around 1.2G with some form of trail braking involved.
Estoril Circuit has had completely fresh tarmac for a few months with greatly improved grip. The trackday followed a Test Day as well so there was a decent amount of rubber.

All in all for the price they are not bad. For a 195 or 205, Federal 595RSR are I think still a better option, AD08R better still. By the time the AR1 are heat cycled out, the AD08R would still be almost like new. The new Federal RS-PRO are also promising but no one here has really tested them.

At the 245 price point, it's not bad and they deliver decent performance, considering there really isn't any other choice its a no brainer for high power cars.

I wouldn't hesitate to buy them again if the decent pricing continues, but for track use only as the vague feeling, noise and wear are not worth it.
On track even after many heat cycles they will last a relatively long time and provide tons of fun in the process.

How did you rate the ZZRs? According to some they are quick. Shame that they never combined the ZZS 235-40-15 mould with the ZZR compound.

The Australian Rx8 Cup uses these tires. Maybe you can get in touch with Rick Shaw Racing or find them on FB to get some more info.

Hi,
I was mainly driving with R888 205/50, but several years ago Toyo price went up a lot and in my region, so they became in the same price range as ZZR.
i can't say anything bad about them(i did manged to get 1 faulty tire which lost/disbonded outside thread). They seem to last maybe slightly longer, but my local track got new tarmac so its hard to tell. Grip wise was also ok. As R888 used to be best bang for the buck in my region in Europe it was my favourite, but noe when th eprice on toyo/avon is similar its down to personal preference. I did trackdays only- no wheel to wheel.

See video posted below. I fail at YT links again.

this might help you

Interesting video. One point to consider is my experience of the 80TW AR1s was that they heatcycled fairly badly, which from what I've read, the RC1 doesn't.

Jeez that necro bumping thing is real. Deleted my post from the other thread.
I am now in a serious money pit situation with these. Not only it's the first Nankang sport tire in the country, it's the first miata related size in any competitive-size tire (other than stupid 16 oem).

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What I got from that video was that, if he had driven the Nankangs as he drove the RC1 on the RC1's last hot lap, the Nankang would have won by quite a bit more. The Nankangs had higher braking grip, and higher cornering grip, and yet top speed went to the RC1.

It would be really nice to see them do the same test after each set of tires had say 10 heat cycles.

Picked up a set of 245 AR-1's for 15x10 Jongs. Should have them mounted soon.

Picture shows 225 Rival mounted on 15x8 by comparison. They look meaty.

https://cimg5.ibsrv.net/gimg/www.mia...44d0fef984.jpg

Did you get these mounted?

I’m interested to see the fitment. From pictures I’ve seen (a lot from r compound’s social media), the 245/10 and 225/9 look a lot more stretched than my 205/8 AR1s. This makes me wonder if the 225 is more like a 215 and the 245 more like a 235, so perhaps I want the 245 for my 9J 6ULs?

From the specs I'd say the 205 is actually a 215 and the 225 and 245 are true to size.

Comparison between the 225s and 245s on 9s would be an interesting one.

225s are NOT true 225s more like 215 usable tread. 245 and 205 much closer to rated size

The 225 are not worth the cost, much more effective to buy 205 or 245.

On a more important note
Due to current EU laws (aka Gripageddon™) that mandate tyres with an F rolling resistance rating cannot be sold, basically all semislicks have been re-designed in some way to achieve at least E rating

AD08R is now dead, out came the AD08RS
Nankang quietly revised the AR-1 without changing names, only refering to the new 2019 ones as `100TW` in their documentation:

From the UK website:
Unknown if there is any effect on grip...but its dubious that they have a custom compound for just the EU while maintaining the same price point. Ditto for AD08RS

245's mounted on 10's can be seen here:

https://www.miataturbo.net/build-thr...6/#post1535874

Agreed. Obviously established knowledge says 225/9 and 245/10, but these seem to run a little narrow vs similar tyres.

Not quite what you are after, but 225/8 and 245/9.

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Gripageddon™!! We need to raise this as an issue. It's truly ridiculous that tyres essentially designed for driving in circles are illegal due to the amount of rolling resistance they have.

I did notice Nankang reclassified their tyres as XL which is a clever move, since it allows them to have higher inflation pressures for the tests. Still not sure what the actual differences are, but the AD08RS looks like bad news.

Of note, the 220TW Federal updated compound for the new regs seems awful vs their old 140TW compound.

The lack of good tyres for anything sub 19" in Europe is really a problem. None of the super 200s, limited sizes of traditional R compounds (eg no 225/45R15 Toyo R888R), no good sports tyres, anything 580 OD and 15" is full on energy saver spec. I'd love a Conti Extreme Contact DW for wet trackdays and 245 VR1 for everything else.

Thank you! It does look like it's full racecar stretch!

I guess then this gives two questions pertinent to me.
1. What is the best Europe available 15" tyre for my 9J 6ULs. Is it the 225 or the 245 AR1?
2. What is the best Europe available 15" tyre/wheel combo that can be run on an NA. I guess this would be a 245 AR1 on the new 9.5" Konig?

Leftist governments something something something.

This is probably a factor, but I think the biggest is politicians being seen to be doing something, rather than actually being helpful.

Of note, I found two pictures of the 225s on 9s. Oddly the first doesn't look as stretched as the second!

225/9 left, 245/9 right.

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225/9 on the second picture

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I bought 245s. Will see how I get on. Suspect I'll need a 5mm spacer and it won't be ideal on a 9J, but it was either that or an over stretched 225 AR1 or some crappy Federals.

Can you mount these in 225 on a 15x8 6UL ?

Some thread necro. Anyone had any experience on these. Thinking about running these this year as a gap between Super 200's and Purple Crack.

very good bang for the buck. relatively heavy but decently sticky. fills that TW gap perfectly based on my experience

A local guy ran them in place of Hoosiers last autocross season (on 11”uls)- everyone who drove the car all rated em 70-80% the grip of A7s. I think you’ll be quite happy- if you follow Greg Peters they are his next set of tires, so I’m sure a review from him will be coming.

ill be putting a set of 245s on my car but winter.. no testing until closer to summer. .

Nothing against Gregg Peters, but I doubt his review will be very relevant to what I do with my car.

There's few track videos of my Miata running 245 nankangs and Bmw ZF 6speed on my youtube channel, more videos coming soon https://www.youtube.com/channel/UC6N...YfpYkgyhN1XoQ/

I have it albeit at a 205. Noisy af on the street. Very heavy tire that also induces nvh.
Plenty of grip but very "understeery". Had to have a 4 click difference back to front to balance the car.

We got a batch of these for our cars now. Still winter here but testing this summer.
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We tested those last year against the RC1 and Toyo RR in the same size. Controlled test, 3 drivers, same car, stickers, pressures optimized.
RR was fastest and dealt with overheating the best. Far more precise steering than other two.
RC1 (old compound) was roughly tied with AR1 for laps. Best AR1 lap was faster but average of best 10 about the same. RC1 took 5-8 turns to come back after being overdriven.
AR1 had worst steering response. Not terrible, just not quite as good as RC1 and nowhere near as crisp as RR. AR1 also took 5-8 turns to come back after being overdriven. Pyro temps on AR1 were nuts, 220-240°f

RR was fastest on 1st or 2nd lap. If cooled for a whole lap, we could match that best lap in the same session. The RC1 and AR1 were always fastest on 1st lap then impossible to match that lap no matter how much we pedaled it. That indicates a compound and casing that develops its best grip way below 200°, like a street tire. Wear on AR1 was severe. Less wear on RC1 and almost no wear on RR.

In short, the AR1 is a cheap, low tech but very sticky street tire. The RC1 is about the same but runs much cooler, indicating it would have a longer cycle life. The RR is a real race tire. A good driver on the RR's could click off endless laps that match the best AR1 and RC1 laps.
AR1 a good time attack and cheap HPDE tire. RC1 a better budget race tire. The RR the best combo of wear, grip, response but they are not cheap. You get what you pay for.

Sound about right for my high power(400+ whp) street driven car that sees the occasional trackday use then. the RC1, and RR isnt really something i can use for street use in norway. It needs to have some thread pattern, and E markings, and be available here. ill consider the RR if i go for a extra set of wheels just for track use :)

Any one tried these at autocross? Curious to if they would heat up quick enough to be better than a Rival S, or if they are more in line with the old NT01s. 245s or 225s for that matter.

They heat up fast. More like a Rival-S 1.5 than any other 100TW

Had some disappointment yesterday. First session on my new 245 AR1s, bringing them in gently for first heat cycle, did 3 laps, came in to check pressures an front left low (clockwise circuit). The tyre had failed and was letting air out, so that was the end of my day!

Has anyone else seen this or should I just categorise this under bad luck?

https://cimg9.ibsrv.net/gimg/www.mia...689bbd1c0c.jpg

Looks like a possible belt separation. Am i seeing the face of the tire has a swollen area?

If so, that is commonly caused by either a cut in the belts in that area from bead to sidewall to tread to other sidewall to the other bead or from striking an object at speed. I have seen a tiny cut in a sidewall cause a massive bulbous body in the tread.

It's good you were attentive to your tires and/or the feel of the car and didn't get hurt.

Unless I am missing something, this just looks like a puncture. There is no bulge indicating a casing or tread separation. That is a fairly large puncture. I would scrap the tire.

No swollen area, just that damage. Yep, could have been a lot worse. Also lucky I had a spare to get home, I often don't take one!

I haven't seen a puncture like this before, but I can't see what else it could be. All the other punctures I've seen on track either have clear witness marks or something visibly still in there. Agreed, at least it happened on the first heat cycle so I can get away with only 1 tyre rather than needing a full set.