15x8.25 ,25 offset
 

does anybody know if 15x8.25 wheels,with 25 degree offset will fit a 90 miata

with 205,50,15 tires

GREAT question! Offset is measured in MM and the other key variable to the question is ride height. But even so you would have to be pretty extreme for that not to work.

This is what 15x9s with a 31mm offset and 225s with a 5" ride height at the pinch looks like.
https://www.v8miata.net/attachment.p...ine=1443215302

The fenders are rolled and even though they are big they never hit.
https://www.v8miata.net/attachment.p...ine=1443215302

So follow me here. The 31mm wheels pictured here stick out 6mm less than your 25mm offset wheels do. But at 8.25 wide your wheels are 19mm narrower with half that being inside and half outside. So your wheels with the same 225/45-15 tires would have 3.5mm more clearance to the fenders than what you see in the photos.

But you want to run 205/50s so we need to adjust. Tire face and section widths vary by model but just the raw numbers on tire size gives you another 10mm clearance to the fenders from 225 to 205. So you could put 10mm spacers behind them or go to a 15mm offset wheel and still have 3mm more room than what you see in the photos.

In other words yes it will work!