Tires

I have been driving on Kumho Ecsta PS31's for the past 15k miles. These are 400TW summer tires but they have handled reasonable well in the wet and "Texas cold" for me. 185/55/15 and 205/50/15, but it appears they do also make the 205/45/16 so you should be able to get a stock size set. 

After 15k of spirited driving a quick eyeball says I have 7/32+ left on the front and at least 6/32 left on the back. I can measure some other time. If you ever happen to be a bit further south or I a bit further north, maybe you can get a feel for them. They will probably be coming off of my car soon anyway as I'm switching wheels.

Posted by: @desertwanderer

Hello all! I need help with tires. Please understand that if I knew everything about tires I would not ask. I plead ignorance that I am trying to correct.

I have a 2005 Spyder with all stock wheels. I daily the Spyder in central Texas in all types of weather. I have a great 40 mile commute daily on twisty roads and I enjoy the hell out of the Spyder. I bought a new set of tires when I bought the car (S Drives in 195/50/R15 on front and 205/45/R16 rear) and they have been good. With 21000 miles on them the rears need replacing and the S Drives are no longer available.

I need help finding a new set of tires. Please correct me if I am wrong but I do not think that having different tread patterns on front and rear would be a good idea.  Discount Tire and The Tire Rack have not come up with anything. I want the best tires that I can buy for my car. I do know that the replacement for the S Drives is the Advan Fleva V701 (best as I can tell) but they are not available in the appropriate sizes. Any suggestions?

Finally, if I am forced to make different than stock size tire choices, how does one go about that? Is the main requirement that the tire height stay stock? I like the Spyder stock and I do not want to screw that up. I have only replaced the struts and springs with OEM replacements and done a little bracing. Otherwise, all is stock.

Thanks in advance for you help!  

 

That staggered setup is going to keep costing you half-sets of tires, and PitA points. I humbly recommend considering going square. Lots of options will open up. It is a trade off, but IMO, it is a good trade.

Otherwise, yes, you should try to get as close to OE spec as possible. You will probably discover that you will be forced to go with 195 in front to match much of anything.

Good luck. I just went down this road and it was challenging to find sets, then have them also be in stock, but there are a few sets still to be found.

Good luck is all I can tell you.

I would try to find stock sizes as much as possible.  Failing that 195 for fronts is not too horrible but 205 just kills the car as far as fun to drive on the street.  It ends up being more like a normal car than a quick responsive go kart.   
One of these days my last modification is going with the wheels I originally wanted (SSR comps) and stock tire sizes in the extreme category.  

Thanks to all for the help! I still, however, cannot find even a single set of tires in 185/55/15 & 215/45/16 or 195/50/15 & 205/45/16! I can only find the front tires and the back tires in different brands. I have never run different tread types front and back because it seems to be a very bad idea. Please feel free to correct me if I am wrong.

Marsrock, I could not find the Kumho Ecsta PS31's for the rear (16's). Could you perhaps point me to a possible source or at least evidence that they make that size?

Finally, I will confess my ignorance as to why the setup is staggered to begin with. Again, I am not trying to second guess Toyota but I plan on driving my Spyders from here on. I really would like to have more tire choices if those choices do not leave me with a Spyder that drives like a normal car. What would I give up with a square setup?

Thanks in advance for your help!  

Never mix and match as that would be disastrous.  Different compounds that can behave differently at varying temps and different sidewalls can lead to unpredictable feel. 
When the subject comes up regarding tire stagger and the rational they will site safety from oversteer but that is not the only reason. The crisp lively turn in response added to the least amount of polar inertia is the enjoyment of driving mid engine car.  The lotus Elise front tire size is 10mm less than ours.  There are other reasons like keeping the unsprung weight to a minimum which can also pay dividends in feel and grip if the damper can do it’s job more effectively.  

let me search TireRack and see what the current options  are. I’m also in the market for new tires but I run different sizes because I chose looks over performance. 

Fudge the tire numbers a little, no big deal. For example, you can get the Yokohama Avid Ascent GT (Grand Touring All Season) and Yokohama Advan Fleva V701 (Ultra High Performance Summer) in 185/55R15 and 205/50R16. 

Bump that up to a 195/55R15 and 205/50R16 and you can get Dunlop Direzza DZ102 (Ultra High Performance Summer), the V701s, Hankook Ventus V2 Concept2 (High performance All Season, I ran these are they're good tires), the baller Dunlop Direzza ZIII (Extreme Performance Summer), Toyo Proxes R1R (Extreme Performance Summer), etc. 

With 195/55R15 and 215/50R16 you can get the Direzza Dz102. 

Going from the stock 185/55R15 to 195/55R15 is a measly 1.02% diameter difference. The difference between stock 215/45R16 amd 215/50R16 is 0.87% and the difference between stock 215/45R16 and 205/50R16 is 1.02%. No biggie. 

We have a stagger so the car is "safer." More meat on the back means less chance of rear traction loss, aka more understeer. As for diameter difference, I think that's aesthetic. 

I would get the 185/55/15 and 205/50/16 in the Yokohama Fleva .  Yokohama is a top tier tire manufacture and if they are the S.drive replacements they should be good. 

To add to Dev’s caution about mix/matching treads or manufacturers.  ONE time I mounted a pair of different brand/compound/tread style tires on the rear axle.   Holy crap!  The car was frightening.  And I’m not talking about autocross or track - I’m talking about driving on the street.  I would scoot around a 90 degree corner, and the rear felt like it was sliding.  I had to make numerous steering corrections after the turn.   I couldn’t even make lane changes without scaring myself.   My uneducated guess is that the sidewall stiffness was so different between front and rear, causing all the erratic behavior.     Lesson learned for me.  I only put the same brand and same style tires on all four!

With mixing and matching you can get anywhere from wild to mild. Wild is better than mild because at least you will know you cant count on your tires. With unassuming mixing you will think everything is fine and when you need the tires the most it will get squirrelly. 

 Another interesting fact is that  OEM supplied tires can look virtually identical in every way to tires sold elsewhere but they can be different. An article I read on the subject stated that the difference is in the sidewall specs that is specific for the car.    The tire manufacture works with the OEM to make specific tires for the vehicle and it is reflected in a tire designation code on the sidewall.  

How much of a difference does this make, I don't know but if car manufactures go though all this trouble it makes you wonder that there is a lot more about tires that we cant assume and generalize. 

@desertwanderer

https://m.tirerack.com/tires/tires.jsp?tireMake=Kumho&tireModel=Ecsta+PS31&partnum=045WR6PS31XL

I would not be surprised if you had to shop two different dealers to get your set. But there are at least a handful of manufacturers making the sizes we need still.

Wow! Thanks to everyone who took the time to help get me pointed in the right direction! This is much appreciated! I now have options!

Thanks Again!

Thanks to everyone for the help! To recap I had S Drives in 195/50/R15 on front and 205/45/R16 rear. At 21,000 miles the rears were gone. I went with Dev's choice of 185/55/15 front and 205/50/16 rear in the Yokohama Fleva. The car has never felt this good before! The 185's in the front really feel so much better than the 195's. 

Whatever the reason I absolutely love this set of tires. Thanks again to a community of folks who led me to this most excellent choice! 

Very good to hear. When I have the opportunity to drive a Spyder that has the 185 fronts it feels like no other car with its crisp turn in and a lot more thrill. As long as the front damper and alignment is in order you don't get some sort of exaggerated understeer that people warn about unless the car is flawed. 

The worst case is the stock Spyder might have initial understeer bite on the tightest of turns when pushed to the limits  but  it passes quickly and then the rear will kick out.  You can actually dial it out by simple alignment but not necessary at all.