That's the width of the tire I think in mm, 205 is a wider tire than 195. The LS Mesh wheel dimensions I believe are 15x6, they are made to work with a 195 tire. 15x7 would be 205 and 15x8 would be 215, etc. By mounting the wider tire on a thinner wheel you are going to have a "doughnut" effect making the sidewalls have to curve in to meet the wheel.
A 205 tire on a 15x6 would look bad, the tire would look really fat.
I assume you mean you like the look of a stretched tire, I have 15x8 wheels and run a 205 tire and I have a little bit of stretch.