I want to go from the stock wheels and tires (14" rim) on my 1990 miata to a 15" rim with some street tires. I have been doing my research and from what I can see a 15x7 rim (I couldn't find the off set) will fit with out having to roll/pull fenders witch I don't want to do because I don't want to f it up. I'm not on coil overs so I can't adjust ride height. I have also read that 15x8 with +36 off set will fit with out rubbing and with out having to roll fenders... As far as tires go I really only use the car for daily driving (but I drive it hard when I drive) I would like to get in to more auto cross this summer as well. Any suggestions on a good all around tire? I make stock power. Also only certain tire size will fit on certain rims? What's a good rim size and off set to run with no rubbing and not rolling fenders? I'm sure that these questions get asked all the time but any and all help would be awesome, thank you for your time

 

Goodwin Racing's website has most of the available options for Miata fitment for cheap. 15x7 will fit with any stock setup. 205/50 15 tires will fit them and there are multiple threads espousing the virtues of most of them, and even a tire hierarchy thread.