Big wheels on Miatas?

I was curious if anyone had experience with tall wheels and low profile tires on an MX-5. I saw some 18'x7' wheels with 215/35WR18 Pirelli P7000 on a demo program online and wondered if this cool looking dream was actually possible. Anybody out there try it yet and did you like it??

It's been done. IIRC it required fender mods (rolling the lip? removal of the inner fender? both?) and still scraped short of full lock. You'd also get all the 'benefits' of heavy wheels and skimpy sidewalls, including terrible ride, poor acceleration, skittish handling, and bent rims. The one case I remember, the owner was disgusted and went back to 16s the next week. But hey, it's your car.

It would work on a show car, but forget about it if you actually want to drive the car!

Got 16's on my 91 look's very cool I wouldn't go any bigger then 16 ..look's too dumb 17's and 18's are too much rim for a such a little car SliverStone 91

..look's : too dumb 17's and 18's are too much rim for a such a little car : SliverStone 91

Whenever someone talks about doing this, I always ask 'What have you got against functional sidewalls?' Never got a good answer to that. My '96 has lightweight OEM alloys mounted with Toyo T1-S's in 195/55-14. I don't think I've ever driven a better combination.

18'? Might as well wrap rubber bands around 'em!

Jerry & Serrano

I know I haven't. Just got back from a 3-hour zoomzoom. The car is so well mannered now, and more competent than ever. In our favorite 'handling evaluation' sections, we went faster today than ever before, and I never got close to running out of safety margin, nor corrected for a single bobble. My steering wheel grip is lighter and my mouth doesn't get dry. The car whispers 'go for it, I can handle anything.' I know better than that, but the limits almost always involve vision, not adhesion.

Stick a fork in it

....but the wagon wheel look seems to be where it's at these days. 18' rims (even with rubber bands on them) should still give plenty of ground clearance for light duty off road and small stream fording. To counter the unsprung weight you could always shoehorn a 21' sub in the trunk.

Do you inflate your T1-S's to 44psi MAX, or 28-32? If the latter, that might explain the plush ride you describe and like. Did you try them at 44psi? They may provide the proper rolling diameter closer to that pressure level.

I am curious as to where these tyres can be found at a good discount.

The maximum pressure is stated only as a safety warning, beyond which the manufacturer won't be responsible if the tire explodes because you overinflated it. Automobile tires are NOT intended to be inflated to the maximum! At 44 psi cold, a 195/55-14 T1-S on a stock 14x6 wheel will probably curl up at the shoulders, especially after it heats up and the pressure increases further, yielding a smaller contact patch. It will also be more prone to punctures and other carcass damage.

I determined that 29 psi (cold) was adequate for my T-1S driving by adjusting until the scuffed area extended the proper distance up the tread shoulder, about 1/8', when pushed hard enough to slide. They do not roll under at the limit of adhesion, and while more air might make them a little crisper, it won't increase grip. In fact, it will decrease grip, especially on rough pavement. For best performance, as a rule use the softest springs, shocks, swaybars, and tire pressures you can get away with. I might go a little higher for autocross.

tirenet.com seems to have the best prices

Not to 44 psi!! I bought mine for performance! The way I understand it, from a performance view the best pressure is the lowest that does not let the sidewalls roll over. The lower the pressure, the more cornering g-force the contact patch can put out if it is not corrupted.

Those performance tires have stiff sidewalls.

No. There you have me.

Actually, I would think the thread is so stiff it does not elongate. I would guess you are thinking of sidewall flex reducing the distance between the axis and the ground. That is irrelevant for rolling diameter.

Check the vendors at miata.net.

I found that out in spades. I brought my miata home wiht 47 PSI in her shoes. It felt great on the corners compared to my truck, but after dropping the pressure to 29 or so, it corners like it's on rails. With 47, aside from potentially killing me, it would slide. Now I really have to work to get it to slide.