I have a brand spanking new 2018 Hyundai Sonata that as soon as I drove it off the lot I noticed it idles rough. Not horribly, but very noticeable. Not only do the RPM's drop a little but you can feel it.
I spoke with dealership and they said things like it could be dealership gas or something about the fact that this car was hauled from Houston and could have had extra moisture in the tank. After going through a tank of gas and still having issues I sent it to them and their mechanic even drove it for several days himself so he could see if there were any issues and he said he found no issues.
Now trust me when I say this, I'm not some kind of left brain perfectionist that complains about everything and trust me when I tell you this thing idles rough, sometimes it even feels like it's about to die but doesn't. I've had plenty of older cars that idle rough, most of the cars I've owned have been older used cars, this is one of the first new ones I've bought.
What can I possibly do to fix this issue because the dealership won't acknowledge the problem? I know how to work on cars but only when I know what to fix, I have no idea what to even look at on a brand new car and there is literally nobody on the web talking about brand new 2018 Hyundai Sonata's idling rough.