Make sure you speak to your local Kia service center and find out what conditions you are supposed to follow. If you have any mechanical issues during the warranty period, you don't want your dealer claiming insufficient maintenance based on local weather conditions.
I live in South Eastern PA, and I have all my oil changes covered for the life of the vehicle. When I brought my vehicle in for the first service, which they scheduled, I was told that I need to follow severe service schedule conditions because of the salt used on the roads during the winter.
I think it's just a scam to try and get you in for the other mileage service dollars. I have a car wash plan that provides unlimited car washes along with an undercarriage wash. This should take care of most of the salt during the winter. When I get the oil changed, the dealer does a free multi point vehicle check anyway. The dealer will let me know when they think certain items need attention at the minimum levels, the point when they think they can justify me giving them money.
In my opinion, all of the fluid systems, except the engine oil, are in closed systems which should only be affected by runtime and system operating temperatures. Since engine oil contacts the Internal Combustion Engine (ICE) cylinder walls, it come in contact with whatever is sucked into your air cleaner. Most large particles are trapped by the intake air filtering system. This biggest problem is when the roads have been salted and are wet. The salt is dissolved in the water and aerosolized. I'm not worried about normal dirt particles because those are pretty much filtered out by the air filters. The salt air is sucked into the cylinders and can be mixed into the engine oil as the piston rings go up and down the walls of the cylinders. Other possible routes of oil contamination could be by the intake valve seals.
Besides, what if you drive very few miles when conditions are considered severe? Why should you be forced to follow severe conditions?
If I'm way off base, please educate me.