NB2 Miata Tire Size on 15x7s

I'm getting some new wheels for the nb2 and I was wondering what a good tire size and tire would be for a daily/track car. They are 15x7s that weigh in at 12.2 lbs. I was thinking 225/45s or 205/50s. What would be better? Also, the tires that I've been looking at are the azenias rt615k. Any suggestions in that department? Thank you.

205/50/15 is what I've always installed on my Miatas. The 225s will pinched some and would better on an 8" rim.

In reply to DeadSkunk (Warren) :

Ok, what about 215/45s? I have heard of some people running them, but they dont seem very common. What would be some good grippy more budget tires?

DeadSkunk (Warren) said:

205/50/15 is what I've always installed on my Miatas. The 225s will pinched some and would better on an 8" rim.

This, all the way. Infinite tire choices.

I'm currently on 205/50s too.  

I'd run 205/50s as well. I ran 205/50 Rcomps on a 15x8. 

The Cali Miata people with track records say 205s for 8s and 225s for 9s. Its advice that's worked well for me with stock power. Not sure about 7s, but if you're not worried about ultimate track time 205s would work well enough.

205/50 or 195/50...both work no 7's.  Don't do anything wider.  195 is shorter and gives a smidge more oomph on accel...feels sportier.  But less choice of tire model.

As for the model tires...come on, guys.  The answers are all right here: https://grassrootsmotorsports.com/articles/track-tire-buyers-guide/

TL;DR: 615K+ is pretty much not the answer to any tire question these days.  Unless you are putting tons of street miles on it, mount RE71RS and thank me later.  If you're being thrifty, they do coupons/sales several times a year...including one at Tire Rack right now.

Someone said to me recently that the RE71rs is like magic. I can't disagree. 

I'm running sparco ff1s too with 205/50 Conti ECSs.  
 

205s for tire choice, but 195/50s on 7s are nice on a street Miata.  Personally, I prefer 205s on an 8 inch wheel (225s on 9s) compared to 7s.

195/50-15 on 15x7:

205/50-15 on 15x8:

In reply to Rodan :

What tire is that?  That is the way 205/50s on my RX-7 sat... on 6" wheels.  I cannot remember what those were, probably some forgettable Yokohama.  They came with the wheels. It was so long ago, all I remember is that they sucked but at least wore quickly.  

205/50-15 on 15x7 is a good street setup. Don't let the track dudes talk you into 8" unless you are actually trying  to win track days. 

In reply to Pete. (l33t FS) :

The 205s are Conti ECS, 195s are Yoko Advan Fleva 701 (that's a mouthful...).

Keith Tanner said:

205/50-15 on 15x7 is a good street setup. Don't let the track dudes talk you into 8" unless you are actually trying  to win track days. 

I'm curious; what's the advantage of the 7" rim for street driving? Or is it just that 7 vs. 8 doesn't matter for the street? 

In reply to CrashDummy :

The 8" wheel gives a 205 a little more 'stretch', which supports the sidewall better for sharper response... The difference is small, but desirable for track work where you're looking for every possible advantage.  The same tire on a 7" wheel will have a slightly more compliant ride as the sidewalls will flex more.  Nothing wrong with a 205 on a 7" wheel on a Miata.

I like 195s on a 7 for a stock power street Miata because it has the sharpest response and lightest weight on a street car where absolute grip isn't as much of a consideration.  Too much grip on the street = boring to drive.

In reply to Rodan :

Exactly. The reason for the extra wheel width is to stiffen the sidewall - an 8" is technically too wide for a 205/50-15, according to the Tire and Rim Association and some tire shops won't even mount them. This can lead to more harshness on a road car. This sidewall behavior is why I run 225s on a 9" wheel for track work but use a 225 on 8" for the street - and why I used 225s on 8" wheels for the Targa Newfoundland's rough roads. Yet another example of why you don't necessarily want your street car modifications to be driven by what works best on the track, it's all about the best compromise for your use.

The weight difference between a 195/50-15 and a 205/50-15 is pretty small - the Yokohama Fleva is 17 vs 18 lbs. I'd pick the best tire that came in either size.

Keith Tanner said:

In reply to Rodan :

Exactly. The reason for the extra wheel width is to stiffen the sidewall This can lead to more harshness on a road car.

My "street" setup for the GRM ND2 is 205/45-17 ECS on the stock 17x7 BBS.  Totally softens the ride quality of the stiffer springs/dampers I have on there now.  Night and day from the 245/40-17 RE71RS or CRS on 9's.  And those get even worse as the tread wears down.  Zero compliance.

Can confirm that 205 on 8" is quick but rides like a cement truck.  Much better on 7" wheels.