NHTSA Complaint #11648155 — 2024 KIA EV9

When you're at speeds greater than 15mph and hit a bump or encounter a surface irregularity (pothole, expansion joint, etc.), the Kia EV9 GT Line goes into a porpoising sway, causing the entire chassis to become unsettled. The swaying is much more pronounced when only one side of the encounters the irregularity, or if the car is not perfectly perpendicular to the irregularity and the left and right wheels pass over the irregularity at different times. The effect is especially noticeable in the rear. This unsettling 'swaying' increases with speed and happens both while driving straight and through corners. The rear end feels as though it's hopping or skipping from side to side. Out of all the vehicles I’ve driven—and I’ve driven quite a few—I’ve never experienced anything like this. During wet and slippery conditions, driving over small bumps or manhole covers has even caused the vehicle to lose traction and begin spinning - even while traveling at 25mph in a straight line. I purchased the EV9 in early 2024 and it has had the issue since delivery. I have heard many other EV9 GT Line owners complain of similar suspension issues and I am frankly surprised that there has not been a string of crashes and fatalities linked to the issue. I have spoken to the Kia dealership several times but because the vehicle is new they claim that they have not heard any other reports and they do not have the experience to diagnose or fix the issue.