I've seem to have been using a few different tires recently. I compared Goodyear Eagle F1 DS-G3s and Yokohama S.drives. Recently I got some Dunlop Direzza SPort Z1 Star Specs, I got them on new wheels so I could use them as track tires, but I was also seeing how they'd be as street tires, and comparing them to the others tires the MINIs are using. I don't know how much, if any, of the differences I'm seeing is due to the new wheels (11.5lb vs 21lb each).

The upshot of my experience is the Direzzas are great tires, have a surprisingly comfortable ride, but are a little noisy.

Performance wise, the Direzzas performed much as I'd expected, which is very very well. They felt very planted, glued to the road (to use a cliche which fits). They do seem to allow you to put more power down coming out of a corner. Accelerometer data (using the iPhone) seems to back this up. In the dry the Direzzas generated slightly more cornering gs than the other 2 tires (like 0.03g more), but I could get more forward acceleration while pulling those gs. On one particular corner the all the tires will pull abut 0.9gs lateral, but the Direzzas were accelerating twices as much (0.3g vs 0.15g) at the same time.

One surprise was how much braking they can generate. I could get 0.97g braking on flat ground, where I could only get a little over 0.8gs with the other tires.

On the track the Direzzas performed great. I couldn't say they were better than the DS-G3s without doing a back to back comparison. I don't have any data from the DS-G3s to compare to the data I got for the Direzzas. I've never taken the S.drives on the track. I did get data for the runs with the Direzzas and I was surprised to be pulling up 1.2g in 3 directions, the lateral gs were on banked parts of the track so have an excuse, the braking was on the flat so I'm not sure how that happened. The total gs generated by the tires was often around 1g, a lot between 0.85g and 1.05g.

The Direzzas held up better to the track than the GS-D3s did, the DS-G3s had a habit of wearing off the shoulder of the tire. The Direzzas have more tread in the shoulder area to start off with and they didn't wear as fast as the tire. I took about 2mm off the tires in general and about 1mm off the shoulder. At that rate the tire will wear out (after 3-4 track days) before the shoulder wears off, unlike the DS-G3s. I have video of Shawn running on the same track on the DS-G3s: http://homepage.mac.com/barryt/.Movi...unaFebBest.mov and the Direzzas http://homepage.mac.com/barryt/.Movi...AprilBesti.mov (with data). Some people complain the DS-G3s squeel too much, but the Direzzas seem to sing just as much.

As I said the Direzzas were a bit noisy. I've been spoilt by running the S.drives which are surprisingly quiet. If you've never run anything but the stock runflats, you probably wouldn't notice that. Accoridng to my sound meter, the Direzzas are about 2-3db louder than the DS-G3s, the DS-G3s were about 2-3db quieter than the run flats I replaced, so the Direzzas would be just as loud as the runflats. The S.drives are about 3-4db quieter than the DS-G3s. So the S.drives are about 6db quieter than the Direzzas, which is very significant and why I like the S.drives. Subjectively, the Direzzas had a nasty low pitched thrum which would give me a headache eventually.

The Direzza's ride was surprisingly comfortable, it felt about as smooth as the S.drives and make the GS-D3 feel like you're running on square wheels. My attempt at measuring this came up with this:



Which is showing the strength of measured vibration running on the tires vs frequency. That show just about what I'd expect, the Direzzas are broadly similar to the S.drive's and more comfortable than the DS-G3s. Shown another way that looks like this:



Which is the strength of the vibrations relative to the S.drives vs frequency on an expanded scale. The human body is most sensitive to vibration in the 8-16Hz range, the Direzzas look a little rougher than the S.drives, but not by much.

My conclusion is I'm keeping the Direzzas for the track and I'm looking at getting Michelin PE2s for use on the street, (if I could find them in stock anywhere).

 

PE2's are nice, but overpriced. I had them in stock size on some R98 Webspokes.

 

Wow, I suggest Alex of Tire Rack send you 2 sets of MINI friendly size tires every month and you sound test and G's test them. Then post on NAM.

 

Have 4 Direzza Sport Z1 Star Specs on order... should have them in a week. Thanks for the advice!

 

i'd agree with your observations. i have also been surprised by their longevity..as i am now on my second season after about 7k miles, two autocrosses and 2 track days. i bought the re-01 pole positions on clearance as this years track and summer tire....but the star specs aren't ready to die just yet and are just perfect for the dragon!

 

I did get the PE2s, I posted my conculsions here: https://www.northamericanmotoring.co...ml#post2779845

 

i'm now on bridgestone re-01 pole positions.....and missing those star specs

 

i love these tires!
8500 miles of hard driving
i hope to make it a year on them(october)
...no tire even close for the moneyimo

 

Yeah, thanks for the reviews on the differing tires, Btwyx. Since we're in the same area and drive on the same roads, you're reviews on different tires have more of an impact on us bay area drivers, imo. My oem Dunlop runflats are pretty much gone up front so decided to go with the Star Specs in 205/50-16 which will be installed sometime next week. I didn't want to give up performance, but am still not sure if I wanted to upgrade to 17" wheels just yet since tires in those sizes are also more costly compared to 16's. I'll try the Star Specs in 16" first to see if I like it and it doesn't give too mushy a ride that I lose too much of that go kart feel. If I do, then I'll probably go with 17" wheels and tires afterwards. In your opinion, how does the 16" Star Specs compare to the oem runflats in keep the car feel planted in corners? Didn't see if you had mounted your Star Specs on a 16 or 17" wheel.

 

I've got 16" wheels. The Star Specs give me the most planted feeling of any tire I've tried.

I thought I'd mentioned that, but I managed to leave it out. I'm running 205/50-16. The Star Specs are on SSR Type C wheels (11.5 lbs each) compared to the standard Bridgespokes (22lb each), so that may have something to do with it, but I put most of the difference down to the tire.

 

I'm running the SSR typeCRS in a 17",with 215/40 z1's....no compromises of any sort.

 

Interestingly, the Star Specs run a little wider than the Azenis that I had on previously. Same size tire (215/40/17), same wheel, and I get a tiny bit of rubbing in the rear, under full compression. Occurs on the outside edge of the tire, rubbing against the plastic inner fender liner.

 

Grassrootsmotorsports current issue mentions how the Dunlop Star Spec does vs Bridgestone RE-11 and Kumho XS in performance driving.

Worth a look and maybe include the Kumho XS in testing as other tires have been tested in this thread.

 

+1 re. the Z Stars. Very sticky, but on our stud-chewed northwest roads, very noisy, particularly as they get down toward 1/8" of remaining tread.

I've ordered RE-11's to replace them.

 

I hear they wear fast even under street use. ~10K limit.

 

I think I will be able to get approx. 5-6K on my Z1. Only lasted 6 months. Too many track days.

 

Hi guys, I'll be due for new tires in about a month. Basically I want the stickiest road tyre available for a decent price. Noise and comfort are non-issues for me, but I'm looking for something that can take a beating and not lose its tread in 5 seconds...

Are the Dunlop Direzza Star Specs the tyre I'm looking for? How do they compare with the Falken RT-615?

 

The Dunlops are great street performance tires that are trackable. I would recommend them. I run them all summer and I am on my second set already. Sorry, have not tired the Falkens.

 

Agreed. The Dunlop Direzza Z1 Star Specs are smoking good! Nice and sticky, great ride ... not sure that there is a a better road tire. I also use them on the track when it rains (I run Nitto NT 01 R-compounds otherwise).

I am curious about the Nitto NT 05, but they don't come in my size yet...

 

I have a question for those of you who are using Dunlop Direzzas on the track: What cold/hot tire pressures are you running with these tires?

 

R56
36 psi front
37 psi rear

 

Mr. H,

Left you a couple of e-mails regarding WGI. Wanted to know if you are going and want to convoy on Sunday!

 

Thanks, are these hot or cold pressures?

 

Cold psi.

I talked with the Dunlop rep at one of the track events and he said not to exceed 45-46 psi hot on the track for "best" traction.

The difference in psi from front to back is an attempt to remove some understeer. I am still experimenting with it.

 

40 hot, front and rear.