Kia K5
Problems & Worst Years

Fuel system complaints define both years of the Kia K5 in NHTSA's data, with the phrase "fuel tank expansion" appearing as a top complaint in 2021 and again, worded almost identically, in 2023. In the 2021 car, fuel tank expansion paired with the rear seat raising was reported 9 times at high severity, alongside severe stalling and loss of power (6 reports, high severity) and fuel odor detected inside the cabin (4 reports) — a cluster pointing to a tank or fuel-delivery defect serious enough to affect both comfort and drivability. Electrical issues centered on the blower motor and its wiring harness were the single most-reported problem that year at 12 occurrences, and a steering wheel malfunction added 6 more. Four separate recall campaigns touch the 2021 K5: 21V447, 21V519, 22V760, and 25V794, so confirming completion of all four is essential before buying a used example.

By 2023, fuel tank expansion alone had climbed to the top of the list with 15 reports at high severity, and a broader fuel system malfunction added 6 more — suggesting the underlying concern persisted rather than being fully resolved between model years. Structural issues (6 reports) and a sunroof malfunction (4 reports) rounded out the lesser complaints, while a brake system failure logged 5 times at high severity is the one entry that stands apart from the fuel theme. One complaint that year carried the safety-severity tag, and the 25V794 recall, shared with the 2021 model, applies here as well.

Given that both years funnel back to the same fuel tank concern and the same recall number, a buyer should treat recall completion as the top priority when evaluating either year, while keeping in mind that these are owner-filed reports rather than a measured defect rate — the newer 2023 car has simply had less time on the road to accumulate its own history. A pre-purchase inspection alongside verified service records tells more of the story than the model year by itself.