: Is there a formula...



urnodaisy
07-08-11, 03:06 PM
for a recommended tire size based on wheel size and how much the car has been lowered for a '11 V coupe?

For example, if I purchase 20x9 fronts and 20x10.5 rears with D3 competition springs (Drop 0.75" Ft / 1.0" Rr) is there a way to determine the best tire width/height for this setup? A way to make sure there is enough wheel well clearance while reducing the wheel well gap as much as possible.

Or, possibly someone with this setup; what tire sizes have you gone with? I am only considering PS2 or Super Sports. I am open to any recommendations. Thanks!

musclesbmf
07-08-11, 03:20 PM
255 35 20 F and 295 30 20 R (26.97" diameter) or
265 35 20 F and 305 30 20 R (27.2" diameter).

Stock is 26.85" diameter

Mark

aj660
07-08-11, 06:31 PM
What about stock front size and 305.30.19 in the rear. Does this work okay?

urnodaisy
07-08-11, 11:44 PM
Thank you, Mark. Is this what you are running or a suggestion? If this is a recommendation then is there a reason or way you came up with those sizes?

Basically is it just trial and error to see what looks/fits? Was hoping there was a better way other than guessing. Thanks again!

baabootoo
07-08-11, 11:49 PM
Other than reading the other........100 posts, there is no formula since all cars are different, and what you like is different too. Mine was unequal at the rear so I had to compensate for that too.

haterinc
07-09-11, 12:25 AM
You need to keep the OD of the wheels within a certain margin of stock. .5" is usually used. Stock front is 27" and stock rear is 26.85" if I remember correctly.

If you go too far one way or the other you have to think about the abs, stabilitrak, tc, etc being thrown off.

aj660
07-09-11, 09:41 AM
You need to keep the OD of the wheels within a certain margin of stock. .5" is usually used. Stock front is 27" and stock rear is 26.85" if I remember correctly.

If you go too far one way or the other you have to think about the abs, stabilitrak, tc, etc being thrown off.

This makes sense. I want to go with 305.30.19 and I'm not sure if I can do it with the stock front tires on the car.

LV_V
07-09-11, 04:56 PM
This makes sense. I want to go with 305.30.19 and I'm not sure if I can do it with the stock front tires on the car.

Use this calculator (http://www.miata.net/garage/tirecalc.html) to get an idea of overall diameter differences in different sizes. Some manufacturers exact measurements differ slightly in the same size, but its not really a cause for concern.