There are a few things that you may not consider.
1) Hitch Capacity. What is the maximum hitch weight. My 4500lb hybrid has a 600lb or so hitch weight when ready to tow.
2) Does KIA recommend a Weight Distribution Hitch. I wouldn't tow without one. Definitely needed it with my Jeep Liberty Diesel.
3) Frontal Area limit for the Kia? Not sure if that is in the manual. Most smaller vehicles have frontal limit restrictions (the square footage of trailer cutting the wind). This has the biggest impact on the engine, especially at highway speeds. Pulling a 5000lb boat setup and 5000lb travel trailer are 2 totally different games.