The points to remember are these:
(1) The settings for the KIA as with other manufacturors have to take into account the quality of the fuel available in whatever country the car is sold in.
Some of it is not so good!!! but the car is a standard factory setup
(2) The Tunit box when set up will refine the performance and enhance available torque, given that we are lucky to have the best refined diesel here in the UK, it is a long held belief that supermarket diesel is bulked (meaning that additional base materials are added so you get diesel which reflects a price & profit)
(3) In my particular case I find the new Shell a very good fuel, the car smokes less,the car runs quieter, drive's smoother and the further added bonus of more M.P.G.
(4) I drive around a 1000 miles per week so I can see the results in any performance change very quickly....
I work in the motor industry not connected to KIA but I suggest you watch them over the next couple of years, watch out VW/Audi/Ford cos they are chasing you down