18" Tire Question

[ggunter]

Who makes a nice sticky tire in the 315/35 to 335/35 range for 18" wheels?

[Jeff Kleiner]

If you're talking for a roadster you need to be looking at 315/30-18, not 315/35-18.

In that size you have several choices in the 200 treadwear range:

Falken RT 615 (still available but being phased out)
Falken RT 660
Yokohama A052
Goodrich Rival
Michelin PS2 (although it's getting a little long in the tooth)

If you want to step up to a 100 treadwear DOT "R" tire and accept the compromises that limit their use in cool &/or wet conditions (I've run both):

Toyo R888R
Nitto NT-01

Jeff

[BradCraig]

I have the R888R and it will pick up rocks from two lanes over! During my build, folks had me thinking that this thing was going to spin the tires all the way through 3rd gear. These tires do a VERY good job of getting the power to the ground.

[Papa]

I'm a fan of the Michellin PS2. Great traction and long wear with a tread wear warranty. The challenge may be finding them as I've heard they are becoming scarce.

https://thefactoryfiveforum.com/attachment.php?attachmentid=115112&d=1569708513

[ggunter]

Thanks for the feedback, the Mickey Thompson tires just don't grip very well and I wanted to get something with more stickum.

[Ted G]

What is the widest tire I could run for 10.5" wide rims? I would love to go 315 if possible. They are 18" rims

[NAZ]

As mentioned above, the Toyo R888R tires work great. I ran some for awhile and found them to provide outstanding traction on dry asphalt. They are stickier than the M/T wrinkle wall drag slicks I run on my race car.

[Hoooper]

R888R unles you plan to spend a lot of time driving in the rain and cold.

[JohnK]

What are we calling "too cold" for the R888R's? There are plenty of days around here in the winter where it starts off in the low 40's in the morning and might only get up to the high 50's but is still a beautiful sunny day. Is that "too cold" for these tires?

[Hoooper]

I drive mine just north of you in Petaluma, where you are located they will be fine. Ive driven at 45F and they were fine, you just wouldnt want to try to turn qualifying laps at those temps. Definitely when it is sunny and 50s they are fine to drive on and probably still grip better than the 555g2

[Jeff Kleiner]

What are we calling "too cold" for the R888R's? There are plenty of days around here in the winter where it starts off in the low 40's in the morning and might only get up to the high 50's but is still a beautiful sunny day. Is that "too cold" for these tires?

That’s cool enough to be far from optimal and grip will be seriously compromised. The manufacturer recommends that they not be used below 40 and not stored below 30.

Jeff

[JohnK]

Thanks Jeff. Sounds like the 200 tread wear BFG Rivals that I have on there now may be the better all-year tires.

[NAZ]

Too cold is a moving target, depends on what you're doing. I'd just be mindful that traction is limited as the mercury drops so be careful in colder weather. Max traction is supposed to be between 185F & 203F but for tooling around town do you really need max traction?

I live in snow country where the highs in winter can be lower than the 15F lower limit on these tires. At 15F and below the tires can crack. I've driven on mine in 40F temps and never had an issue. But I also don't try to run the car hard at that temp. I have launched the car hard off the trans brake several times when it was 70F out and the tires weren't much hotter than that. Almost a dead hook, very little slip.

https://www.toyotires.com/media/2456/tsd-17-001-coldweatheradvisory_-10172017.pdf
https://parsbrorc.com/?page_id=250

[Hoooper]

Thanks Jeff. Sounds like the 200 tread wear BFG Rivals that I have on there now may be the better all-year tires.

The Rival S is a great tire, but I would disagree. I live pretty close to you and in a slightly cooler area especially in mornings and Ive never found that there is a traction issue with them when acting responsibly in the morning. Once the sun is out, which as you know is like 300+ days a year, the R888R is warm enough and good to go. Im sure the NT-01 is similar.

[JohnK]

That's great to know- thanks! The main concern for me is that all the "fun" roads around here are up in the Santa Cruz mountains. I've ridden those same roads for years on both bicycles and motorcycles, so am very familiar with them. They have a habit of surprising you with wildlife jumping out in front of you, wet patches in the middle of blind corners on a sunny day, etc. I agree that responsible driving and not outdriving your sight lines is paramount, but having some traction in reserve for those "oh *$&%" moments is what sometimes keeps you from going over the embankment.

[Hoooper]

Yeah, since the Rival S is a pretty good tire and I assume better than the 555g2, I dont have a good comparison. I can offer that my traction in the morning when it is 50-55F and the sun is just coming out is pretty good. I make about 500 lb ft and in those morning conditions I still hook all of 2nd gear without a problem. Compare that to the 555g2 where it seems nobody can hook 2nd gear even with less torque and more ideal warmer conditions, the cold performance of R888Rs is really overstated IMO. You just dont want to drive it crazy right out of the garage, and you dont want to drive it below 40F to avoid damaging the tires (when its rarely below 40F during the day here anyway, why torture yourself driving the roadster when its that cold anyway?)

[GTBradley]

I wanted the R888Rs but couldn’t find them in my size in time for autocross season, so I got the Nankang AR1s which are nearly identical in performance. I have a second set of wheels so I can swap out my Nittos which I rely on for cold, rain and high altitude driving. I autocrossed the Nitto 555G2s last summer and they did okay and didn’t change much between hot and cool days. This year I did one AX in the high 70s and one starting in the low 40s with the Nankangs. You don’t notice the difference on the street because you aren’t doing anything extreme, hopefully. On the track, there is a night and day difference. The all warm day I had to try very hard to reach the limits of traction. By contrast, on the cold day I spun the car three different times. In my experience, there is a huge difference between 40° and 70°, just be careful with “sticky” tires in the cool temps and don’t get caught in the wet on treadwear 100.

[BrewCityCobra]

Has anybody run the Yokohama A052's? I am currently torn between them and the Falken RT 660's. Usage will be driving to work in the summers (so daily driving can't be terrible) but still looking to get a few Autocross and track days out of them. Even willing to give up a bit of day-to-day to keep performance so long as it isn't terrible.

[NAZ]

I have no dog in the fight, I don't have stock in Toyo or any other tire company. But you shouldn't be spring-loaded away from any of the stickier tires just cuz somebody says their traction is affected by cold weather without putting some perspective on that statement.

Remember, we're comparing the performance trail-off in the cold of an extreme high performance tire. The R888R is so much better than the all weather "performance" tires some of the high-end sports cars come with that comparing them to the R888R at 40F would be a better way of assessing them. Having driven both on different cars is not an apples to apples comparison but my experience makes me believe that too much emphasis has been placed on cold performance degradation of the R888R. A reasonable approach to driving them is required. If you want a rain tire or snow tire -- the R88R is not your tire. Just like you wouldn't expect a street tire to work as good off-road as a mud-terrain tire.

All tires are affected by temperature. You don't pull out of the pits on cold tires and expect to run the same lap times as tires at optimum temp. You adjust your driving until they warm up.

[JohnK]

I *think* (spoiler - completely uneducated opinion coming) that what gets people in trouble is not the optimal traction of a particular tire but rather the variability in available traction. Unless you're really in-tune with a particular model of tire, the more day-to-day variability in traction based on temperature and other factors there is, the more likely one is to overestimate how much traction they have available. If we use an arbitrary scale of 0-100 for traction, for a street tire I'd rather have a tire that varies from 50-70 based on temperature vs. a tire that varies from 40-90. The latter will absolutely be a better tire in dry warm weather, but that's a huge variation in traction for my little brain to have to manage vs. just having a good feel for a tire and knowing I can count on it to behave pretty similarly in most conditions.

[GTBradley]

I’ll put it another way, logically speaking, a tire that is in danger of cracking because of low temps is obviously harder than one that can handle a larger temperature swing. Is it not also reasonable to assume that a harder tire has less traction?

My point is that if you want to drive in the warm and in cold, high altitude where there is potential for rain a tread wear 100 or even a 200 is not a great choice. Where the triple 5s may have trouble with hard launches and shifting hard they do not have trouble stopping, cold or hot. I would put my money on the wider temperature range tires for all year driving. And therefore, I think the Nitto 555G2s are getting a bad rap for use on these cars.

[rich grsc]

Naz, you might be in a losing battle to get people to understand what your talking about. :(
There Ain't no magic 'do everything' tire. :rolleyes:

[JohnK]

It's OK, keep trying Rich. Maybe one day you'll post something useful.

[GTBradley]

Naz, you might be in a losing battle to get people to understand what your talking about. :(
There Ain't no magic 'do everything' tire. :rolleyes:
The true statement here is, that all tires have trade-offs. My point is that for someone like johnk is that if you want a wider range of use weather wise aka all-year, a tire like the triple 5 is a better choice.

[Hoooper]

If we use an arbitrary scale of 0-100 for traction, for a street tire I'd rather have a tire that varies from 50-70 based on temperature vs. a tire that varies from 40-90. The latter will absolutely be a better tire in dry warm weather, but that's a huge variation in traction for my little brain to have to manage vs. just having a good feel for a tire and knowing I can count on it to behave pretty similarly in most conditions.

If that is what youre looking for then I think you have your answer already in the Rival S. The R888R will vary more when driven with cold tires and on wet roads and if your desire is more focused on consistency than performance the Rival S should give you that wider window so you dont have to be attentive to the road conditions. A 555g2 would likely give an even bigger window, for that matter.

[rich grsc]

Everything I post is useful John, for those that understand.

[CraigS]

5-6 yrs ago autocrossers needing 200 TR tires ran either Rival S or RE71Rs. The general experience at that time was that the RE71Rs were slightly better beginning and end of season but they would need to be watered down between runs in hot summer. The Rivals were better in hot summer and generally didn't need watering between runs. The RE71Rs are gone and the Rivals seem to be fading away now while the RT660 and A052s seem to be the favorites. I just did a quick look for RE71r and found a new RE71RS which is apparently so new that tire Rack has no reviews yet. Something to consider is availability of sizes for your car. Particularly the 315s are not available in many tire make/models. The RE71RS for instance tops out at 295/30-18 and 285/35 19s and 20s..

[GTBradley]

This is an interesting idea from Nitto (https://www.nittotire.com/competition-tires/nt555rii-dot-compliant-competition-drag-radial-tire/):
165782
I don't know if this has been out there for a while or it's new, but it's interesting to me that they designed for compatibility of a drag radials on the driven wheels and a summer tires on the non-driven. They don't make it in the 18" 315/30 but they do make it in 335/30 and they do our 17" 315/35.