But a 27" tall tire on the 17" wheel is not going to be any taller than a 27" tire on a 15" wheel. 27" is 27" regardless of what wheel is in it.
If the car sits up higher, logically, it can't be because of using a tire that's the same height as the original tire. It has to be because of the suspension. Many times the new springs people are using sit the car up higher than original. Or sometimes they've lightened the engine with aluminum parts or by removing a/c components. Either of those things could have happened on the blue car.