I've asked this question here before, but didn't get a real definitive answer.

Basically I had found the very least expensive place to but my tires and have them installed. For a while it was $820 including tax, mounting, and balancing for a set of Toyo T1R's 2 245/30/19 and 2 275/35/19. Then the price went to $860 and then $900. Now I am getting the two rears replaced(the fronts are fine) and it is at a price point that would be $960 out the door installed if I got all four. That is still the cheapest price I can find in the Los Angeles area and at least a couple hundred less than my total cost would be if I were to order online and have it installed at a shop nearby.

I'd like to find a cheaper option.

General Exclaim UHP are about $710-750 out the door installed for a set of four. But they do not have a 275/35/19. Rather they have 275/30/19.

I'd like to know if this setup works. One guy posted in the previous thread I made that he did not have problems. A couple other people posted that this setup will not work well.

So which is it?

 

The stock tire size for the 19" coupe wheels is 26.7 inches, so you want to stay as close to that as possible.

A 275/35/19 is 26.6 inches, or roughly 0.5% off. That is definitely your ideal tire size.

A 275/30/19, rather, is 25.5 inches, which is really short. That's a difference of 4.8%. That means your speedo will register high, as well as your odo; you'll accumulate mileage faster than you actually are.

A useful tool is the tire size calculator at miata.net:
http://www.miata.net/garage/tirecalc.html

Play with it to find tire sizes that come close. Once you find a candidate tire size, look at the specs for the tire at a place like tirerack. For example, look at these specs: http://www.tirerack.com/tires/Spec.j...%3D44YR9RE050A

Look for the Rim Width Range column, and it will tell you what rim widths the tire will fit on.

Another alternative is to look at the specs for the tire model, and scroll through the rows until you find a tire that will fit your wheel and comes as close to 26.7 inches diameter as possible.

 

Thanks for the useful information Trey!

 

Don't think he'll respond, but it is good info.