Need some help deciding on a summer / autocross / lapping tire!
 

Hi guys,

I'm looking around at different summer tires, and I need a little advice. These are to go on my '93 R1.

I don't think i'm at the point where i want to be buying a set of dedicated track wheels/tires so I want something that's good on the street (liveable ride, good enough wear to get a couple of summers out of them), and going to be fun for autocross and maybe the odd lapping day. Here's what i'm looking at:

Falken Azenis RT615

Dunlop Direzza Z1 Star Spec

Nitto NT05 - I'd have to come across to the U.S. to pick these up as they are apparantly not available in Canada.

Budget choice: BFGoodrich G-Force Sport


If you own or have owned any of these tires, feedback on treadwear would be great. If i'm going to spend the $$$, i'd like them to hold up somewhat well to street driving. I do about 10,000 miles each year.

The only tire's I've run out of that group are the RT615's.

I managed about 4000 km of hard driving before they were done, front and rear.

I did make it to one road course type event with them. Each run consisted of 6 consecutive laps (about one minute each). Laps one and two were slippery while the tires heated, three and four were quite nice, but by halfway through lap 5 (5 minutes or less of hard driving) they would get greasy.

The G-Force Sports are not in the same category as the other 3.

I personally have the Azenis Rt615's on my RX-7 and I think they are wonderful for street driving and autocrossing. I have beaten similar cars on slicks with them.

The Nitto's are not worth it.

You may want to take a look at the Kuhmo ECSTA XS as well.

I know the GForce sports aren't really in the same class of tire, but they would be more of a budget approach. I more or less threw them in there as an example of a harder compound street tire that would last on the street, but might still be a fun tire for autocross. I'm pretty sure they get used as a spec tire for various car control schools... i think the skip barber school uses them, but that might just be because they're predictable and cheap.

Good call on the Ecsta XS though. I'll have to check those out for the money

star specs own the world at the moment.
the fastest street tire is probably advan neova, but they cost way too damn much

when in doubt, see what tire national champ STU/X guys run (they have a minimum 180 treadwear)

Star Specs are badass. Just them and some Kosei K1's on his stock suspension Miata made a world of difference.

Star specs!

The Z1 Star Spec is the quickest of the lot, when it comes to street tire classes (treadware 140 minimum). They aren't as widely available as the RT-615 (sizes).
The RT-615 has been around for a few years (2005 introduction) and has been the tire all others have been measured against, for grip and longevity.
The new Kumho XS seems to be in the same grip level, but lifespan and grip towards the end of life are still uncertain at this point, since it's such a new model.

The one thing that the RT-615 has going for it, while the intial grip isn't quite as high as some of the newer models, it doesn't seem to fall off as bad as some of the others.
They do take a bit longer to get fully up to temp than a few others, but in the end, the heat cycling doesn't affect them quite as bad.
When new, there are tires that are faster the the RT615, but towards the end, those same tires struggle to keep up with like-worn RT615's.
All street tires will get greasy when hot, that's unavoidable without killing overall lifespan.
The RT615 is also usually at the lower end of the pricing scale, making them a good choice for all-around use, particularly for those on a budget.

Uh fellas, the Star Spec lost the latest GRM ST-Class tire test, badly. Even the old RT615's beat them.

The XS is the new fast king, the RE11 is right there as well, and the RS2/3 and the Rt615 are fighting for fastest for cheapest. The Rt is still the longest lasting and has best grip at end of lifespan. They're also cheap and come in 14" sizes, which most of the others don't.

Yeah, the RT615 having a 14 and 15 offering is certainly advantagous for us old schoolers. Many of the newer street tire class contenders totally ignore 14", and miss the mark on the 15" by offering a 195/55-15 instead of a 205/50-15. The 195/55 is a bit narrower and taller than the 205/50.
I just ordered a new set of wheels to fit my '83, and will be tossing a set of old RT615's on them to finish off. I may step up to actual r-comps, or stick with the RT615 for the next set of race rubber. The RT615 can be driven to/from events a little easier than R-comps. Too risky when it comes to punctures.

Well I have heard nothing but good things outta the Star Specs. My buddy has RT-615s on his 240SX and they are alright to me, but nothing special. The Star Specs will pick up leaves fresh off the truck with no heat in them :D

I heard the same from a friend who was talking about it elsewhere. We're both running the RT615s.

Gotta read the article, when they re-ran the Rt's they went 34.x's as well ;)

what's the lifespan going to be like if i run the rt615's on the street? approx. mileage?

Average life on the street can be anywhere from 3K to 20K. It all depends on how much fun you have in the meantime.
I know people that have gotten well over 100 autox runs out of a set, and others that are lucky to get 50. The power and weight of the car, along with driving habits, have a lot to do with how long they will last.

On my FB, which weighs 2500 with me in it, I've gotten 4,000 miles and 75+ autocross runs plus 20 1/4 mile passes so far and they still look new, hardly any wear. I should get 15K and another 2 seasons of autocross easily. I also drive the snot out of my car and go on long drives through the twisty mountain roads.

Will do! He only mentioned that one test.

I've only had them on mine for only a few months. I've did one very wet track day, which was 2 days after I put them on, where they did much better than I was expecting. On two dry day events and on the street/back road drives they definitely have been very impressive.

I have the RT-615's. I've ran that at the AutoX, at TGPR(in the rain) and VIR Road Courses for four 30 minute sessions each day, and about 2000-3000 miles on the street. They have performed very well for what they are. They start to get greasy and fall off towards the end of the day on a road course. It's a street tire though so it gives you warning before it does where a R Compound just grips, grips, grips... and then let's go without warning. The thing that surprised me the most about these was the wet grip they had when I drove at TGPR and it rained all day. Don't get me wrong, they aren't an all season tire, but the wet grip they provide for being a performance street tire impressed me. Most people I know of have been seeing around 10,000-12,000 miles out of these tires.

I picked up a set of Dunlop Direzza Starspec Z1's a while back for track use this season. They were reasonably priced as well and the way everyone has been talking about them... they are suppose to be the cat's meow. I'll be back in the states Mid May and I have my first track day May 22-23. I will have track events almost every weekend after that as well as some autoX's thrown in. I'm sure I'll post a review of them but that won't be for another few weeks and I'm sure you are trying to order tires now... so it prob. won't do you any good.

As far as the new XS's and the NT05's, I have some friends them this summer and once I compare my review with theirs, that's what I'm going to base my next street tire purchase on.

All in all I'd say they are all pretty close in performance and if you aren't racing, a second here or there doesn't really matter, but getting more seat and bettering your driver skills does.

I've Top-10'd in autocrosses (60-70 car fields) in the wet on the Rt's. I think they're a better wet tire then Hoosier rain slicks.

As hard as it was raining at times and the amount of water on the track that day, and really having no time on them at all except for the drive to the track, I really wasn't sure what to expect. Needless to say I was pleasantly surprised also.

All this discussion about the RT615 proves why it is the tire that all newcomers are measured against.
The price to performance ratio is just derned hard to beat.
It's part of the reason I plan to start next season with a new set of RT615's, and use them mainly for competitive driving, and keep good summer or all season tires on the other wheels for daily use. The minor amount of intial grip I'll give up, will be well worth it down the road, when they still work nearly as well bald, as they did new.
I'm hoping my current set (at the treadwear bars) will last the rest of this season. I got this set free, so instead of just buying a new set and running them full time, I spent about same money on a second set of wheels to finish off what I have, and still have daily use wheels/tires. They are too worn to be safely used on the street, particularly when the street is wet, but fine for autox/track use except for extremely wet conditions.

My big beef with the newcomers is lack of size availability. Almost all of the dominating ST and STS cars run 14" or 15" wheels, so why aren't they making the new ST tires in those sizes? Nothing in 16" either. Even 17"s are pretty scarce, you pretty much have to have an 18x8 wheel to get a decent "new" tire nowadays.

Very true. The ST/STS classes are full of small cars that can't fit the majority of the newcomers sizes under their fenders, if you could even get the wheels to use them.
The RT615 is the only ST class-leading tire that I am aware of which is even offered in a 14" size. Granted, it only has one 14" size available, but that's still 100% more than anyone else.
More often than not, the newcomers either totally ignore 15", or go with a less than desirable size. The one new tire that really took me by surprise, is the Hankook RS3. I have seen one 15" size offered so far, and it's a 225/45-15.
ST/STS allow a maximum tire width of 225, why is it that Hankook is one of only a small handfull of companies offering the 225/45-15, while the other newcomers are opting for a 195/55-15.
Fortunately, the RT615 205/50-15 has nearly the same tread width as most 225's from other brands.

Hey, I won't see the GRM ST shootout for another couple of weeks so can someone help me out and post up the size of the StarSpec's opposed to the others tested. I'm having a few people tell me it's an irrelevant size compared to the others being tested, but they didn't know the exact size.

So.... can someone post the tire size of each brand tested?

Thanks.

Falken Azenis RT-615 - 205/50/15 - 34.822 Avg / 34.739 FTD

Dunlop Direzza Sport Z1 Star Spec - 195/55/15 (the *only* 15" Star Spec) - 35.209 Avg / 35.061 FTD

Toyo Proxes R1R - 205/50/15 - 34.522 Avg / 35.452 FTD

Bridgestone Potenza RE-11 - 205/50/15 - 34.266 Avg / 34.238 FTD

Bridgestone Potenza RE-01R - 195/50/15 - 34.478 Avg / 34.430 FTD

Kuhmo ECSTA XS - 205/50/15 - 34.170 Avg / 34.030 FTD

For being the tire that has been around the longest, the RT615 still holds it own. Considering it can usually be found cheaper than the others, and has way more size offerings, it's no wonder that it has gained many a loyal follower.

It's the only one with a 14" tire, it's the cheapest, it has the most sizes period, and it lasts the longest. Stick a few events on all of these and the RT's will still be hitting the same times, the others will have dropped off. Especially considering the RT's will last an entire season!

For track (road course) use, you'd be better off in the Star Spec or the Kumho or Bridgestone. Star Spec and Kumho are cheaper. Those tires will handle heat better and stay consistent over 20-30 minute sessions compared to the 615. The RT615 is a better autox tire though b/c it warms up faster and has good grip when colder as compared to the other tires.

In the GRM test, they suspected that the Dunlop would do better if it were the same size as the other tires so don't take the test solely on face value. Read the article and pay attention to the impressions of the drivers as it will give you a better picture of all the tires and you can make a better decision.

i do believe the dunlop's performance while cold is one of its selling points for autocross.
while it may not be the fastest tire in successive testing (where did the Kumho come from?!), they are known for their cold grip, which makes them outstanding in the wet, when you CANT build heat. also, most street tires wont build much heat at all in a standard autocross.

no idea about longitivity, thats just what i've heard from users.

I appreciate all the feedback. I just found out that the star spec's are not available in Canada yet, so if i want em, i have to get my passport together, and make a drive across the border. That might just be more hassle than its worth. RT615's are readily available and not stupid expensive, so that might be the way i end up going

I'm enjoying my RT615 right now, still haven't milked everything from them yet. Wear has been pretty good even with plenty of fun drives. My next tires will probably be the Hankook RS-3 or Z1 if I can't get my hands on some R-comps.

The falkens do get a bit greasy after maybe 5 laps on a warm day. I would have to do a slow lap after that and then I would be able to go hard for another 2 or 3 laps.