What's the thinnest tire I can go on these 18"

[ChiGGz]

I'm having slight rubbing issues since I did my rear camber adjustments, and was wondering what was the thinnest width I can go with

They are:

Konig Monsoons 18x7.5 +40 offset
Right now I've got Yokohama AVS 100 235/40 I was hoping to go down to 220 or lower and possibly a lower profile

EDIT

Im an idiot, its 18"

 

[larsenracing]

well to go with a narrower tire you could go with a 205/45/19 which would have the same roll out or keep the speedometer the same. otherwise a 215/40/19 will give you an overall smaller tire some narrower and some shorter but if your actually going 58.6 speedo will show about 60.

http://www.miata.net/garage/tirecalcold.html

check this out it will calculate your tire size.

 

[larsenracing]

yup, exactly what larsen racing posted. the only thing u need to be careful on low profile is the alignment on your ride.

low profile tires shouldnt change the alignment at all its just when you change the ride high of your suspension then it will change the angles with tire size all you are doing is lifting the car up and down on the same plain not changing any suspension angles. but that is just to the best of my knowledge and understanding of lowered cars and tire situations. i am much more knowledgable about the motor end of things than suspension.

 

[wret]

yup, exactly what larsen racing posted. the only thing u need to be careful on low profile is the alignment on your ride. On dsm, this tends to be a problem unless u do the camber kit to it. If u don't, it will eat up the inside of the low profile tire causing the tire to rip from the inside. It has happened to me as well as others so beware of this. Plus, now-a-days, tires ain't cheap. Remember that.

You are confused. He asked about tire size, not lowering, and it's the toe out from lowering that eats your tires.

ChiGGz, 235/40/19? That's way to big! You should be looking at 225/35/19.

 

[ChiGGz]

You are confused. He asked about tire size, not lowering, and it's the toe out from lowering that eats your tires.

ChiGGz, 235/40/19? That's way to big! You should be looking at 225/35/19.

SORRY! I mean 235/40/18

 

[nightstocker99]

I am buying a set of 225/25/18 rims of of my buddy that is pretty small.

 

[wret]

SORRY! I mean 235/40/18

That's a different story. Did you roll the fender flanges? Is your suspension excessively low and is it adjustable. Did you correct too much camber? There's nothing wrong with leaving a degree or so negative.

There's nothing wrong with that tire size on the wheels you described but if you can't correct the rubbing then you can go to 225/40/18's.

 

[99gst_racer]

SORRY! I mean 235/40/18

Are you trying to go to a thinner profile or a more narrow width?

As far as profile, you can go down to a 35, but I recommend a 40. With the 40 profile, you get better ride quality and a more accurate speedometer.

As far a width, you can do 215 or 225 instead of your 235 profile. I would recommend using the 225.


For 18x7.5 rims, the optimal tire size would be a 225/40/18.

PS - my car is lowered with Eibach Sportlines and it rubbed with 225 tires. I had to take a dremmel and grind off a little bit of metal in the rear wheel wells. This should not be a common problem (I believe that my springs are sagging). I never rubbed with my old 215 tires though. I'm willing to be your car is lowered about 1.5-2.0" and the extra wide width it what is causing the rubbing.

 

[ChiGGz]

WRET: Fender rolling is in my agenda, but Im afraid to do it myself. Something about having a baseball bat compressed between my wheels and my fender with the weight of my rear end scares me. Esp when my fender gap is like barely one thumb high.

I basically eye balled my rear camber (i know i know....) I had it measured before hand and it was about -3 on both sides so I shimmed it with 5 washers. And now here is my problem

The side arm is now 2 mm away from my wheel sidewall and I'm not sure how much play there is at that point. This is why I was hoping to go with 215 instead to increase that gap.

99gst_racer: you mentioned taking a dremel to the fender. Do you mean you did this as a method for fender rolling? I like that idea better than the baseball bat.

I did think about going with the thinner profile to give myself more clearance for the drop. Currently Im with Tokico shocks/springs 1.5" drop. I didn't know 225/40/18 was optimal. Would 215 be too thin for an awd pushing 350 hp? I'll be opting for those tires unless someone wants to say so otherwise.

 

[ChiGGz]

What's the stock tire dimension? So I could calculate it on that miata site.

 

[wret]

What's the stock tire dimension? So I could calculate it on that miata site.

Start with the stock 205/55/16 for a reference. Don't wiry about the clearance at the knuckle (pictured). If there is any clearance and no rubbing, it doesn't get any closer. I am surprised that this is as close as you say with 235s and +40mm offset. I would expect more like 8mm-10mm.

Don't be afraid of fender rolling, it's not hard or destructive.

It sounds like you have more than 1.5 inch drop. That's the root of your problem, but yeah, 225's will help get your tires away from the fender flanges. 215's certainly would but I don't think you need to go that narrow.

 

[bloody_angel111]

215/35r18 is the lowest he can go, if he wants to that is, i wouldnt, but its his car, not mine