Dear Derek,
I don't know exactly what is the reason placing a smaller tyre to the car. Usually what happens is either the standard size or larger size to give better look and more grip (surface area). Obviously you will be experincing both but vice versa, grip will be less and look will not be nice.
Anyway, they will fit however you will practice 2% reduction in actual speed than the speedometer. (i.e. : While speedometer read 60 MIles, you will be actually going 58.8 Miles. Somthing that is not major and would help with radars. I recomend installing the standard size or a 205-60-15.