As you are aware, I installed a Full size spare (using a used 2011 Optima EX 17" rim off Ebay and a new CP671 from [url=http://www.highperformancetire.com]High Performance Tires Store - For Cars, Motorcycles and Off Road Vehicles[/url]), in my 2011 EX, with stock 17" alloys.
Well, I was thinking about putting the spare on Ebay and, upon checking the spare, I saw it was marked as a 16" sized as 125/80D16. I then went to Kiacarparts.net and saw there are 16", 17" and 18" spares available for our cars.
FYI - the donut tire/wheel diameter is 74.99 inches and the 17" stock is 82.66 inches, which is just over 10 percent difference in size plus the wheel rpm's per mile would be 845 v 767.
I will send Kia an enquiring Email about this today but, in the meantime, perhaps you could check to see if you have a 16" or 17" donut spare in your trunk.
I believe they will probably tell me it is ok to run on the donut for a few miles as it is only around a 10 percent differential. However, I will mention to them that living in a large state such as Texas, a few miles here can be a few hundred plus where could you get a flat fixed on a Sunday!
Ok, so if you do check it it is 16" or 17", make sure it has 60PSI in it.
IMHO, they really need to give the option of a full size spare......especially for us living in large states.