I'm looking into the 01 chrome replicas... I found some on ebay that come with 295-40-20 tires.
What do these #'s stand for?
Also... how big are the side walls? I've seen 20's with tires so thin that the diameter of the whole wheel is the same as my 18's and tires. I want somethign that comes close to filling the wheel wells.
Thanks.

 

40 in that im pretty sure is the Sidewall. As stock F1's are a 45 sidewall. I have the Dunlope Sport Sp9000 in 295/40/20's on my 20's check my sig pic and my gallery for better pics. IMO you dont want to do a 45 sidewall with 20's takes away from the rims and doesnt make them look as good. I think 20's look best with the 295/40/20's tires .

 

Argh... so what you're saying is that the 20 inch rims with the 295/40/20 tire is the same total height as stock?
If 40 is the side wall, what does that mean? Total height of the wheel/tire?
Total centimetes of the sidewall?
40 of what?

 

.

 

295-amount in mm across tread
40-% of sidewall to tread.The smaller the percent, the smaller the sidewall (40=118 mm,45=133mm and so on)
20-I guess you already figured out.

Hope this helps

VINNIE

 

295/35ZR20 is closer to the same size as the stock F-1s. I agree with Vinnie, the 40 profile is a better compromise and is only about 3/4" taller than stock. With the change from 3.55s to 3.73s, my speedo was off about 3mph at 60. I have since gone to a 305/40ZR20 and now my speedo is off by about 1mph at 60.

Here's a good tire size calculator.
http://www.miata.net/garage/tirecalc.html

One for gears.
http://www.4lo.com/calc/geartable.htm