Originally Posted By: turnbowm
I have a 2015 Kia Optima that uses the same 2.4L GDI engine as the Sonata and the car performs very well with PUP 5W30 in the sump. When I have any car that's under warranty, I always follow the Owner's Manual for oil specs and grade. Don't want to give the manufacturer any reason to deny a warranty claim. As always, YMMV...
I have never seen or heard of Kia requesting an oil analysis in regards to an internal engine warranty claim. All they have ever wanted from me as a tech is proof that oil and filter changes have been done at least every 7,500 miles. If you have receipts, you're covered. A pic of the receipt with odometer in the background has worked, as have records from Walmart TLE, Jippy Lube, etc. they just want to know it's been done, not caring if you put Amsoil Dominator 15W-50, Rotella 15W-40 or Harvest King SAE30 in it. Don't ask don't tell right?
I may even put Castrol 20W-50 in my 2015 Optima 2.4 next time to "see what she'll do", especially since it's a lease going back in February and I've got 4 jugs I bought at Advance for $1.30 a jug.
Just kidding. My conscience won't let me do it.
Or will it...