If you are changing it on your own, depending on your climate, 5W30 would probably be the grade. I would definitely use a good quality synthetic motor oil. The old go to is Mobile 1. But, by watching Project Farm on YouTube - (he tested several brands) - I will be using Costco's Kirkland Brand Full Synthetic. It has all of the spec ratings to meet/exceed Kia requirements, and it is very inexpensive - 2 x 5 quart jugs for $25. I have been using it in both of my other Kia's and it looks and seems to be an excellent, quality oil. It is made by Warren Distribution, who also makes Amazon Basics (also a good choice), MAG 1, amongst other private labels. If you use a decent quality synthetic oil, the KIA brand filter (at least while it's under warranty) and change it regularly, you will be fine. I change mine every 5K miles, which is less than than recommended interval.