Not that impressive, my 2006 Kia Rio had a 1.6L motor and 110HP at the crank, which is a little better ratio than the Elio. And at the time when I bought the car, it was one of the cheapest new cars on the market. My 2012 Hyundai Veloster made 138HP from a direct injection version of the same 1.6L motor and was definitely still not in the high performance category. The benchmark lately for performance numbers has been closer to 100HP per liter, normally aspirated. Like the Honda S2000 pushing 237 HP from a 2L motor.
That tells me that there is some more performance to squeeze out of the motor before even going with a turbo, sacrificing gas mileage of course.