Kia Optima
Problems & Worst Years

Few model-year spans in this dataset tell as consistent a story as the Kia Optima's 2016 through 2020 run, where an engine oil consumption complaint appears among the top reported problems in every single year. The 2016 car is the standout by volume, with 355 total complaints — the largest figure of the five years by a wide margin — driven overwhelmingly by check engine light and warning light activations, logged 218 times and carrying the dataset's safety-severity tag; engine oil burning through excessive consumption added another 38 reports, with a second phrasing of the same complaint contributing 16 more. Power and regular window malfunctions round out the top five that year, at 12 and 10 reports respectively. Recall 18V907 applies to the 2016 model.

The 2017 Optima shifted emphasis toward misfiring and power loss (39 reports, high severity), excessive oil consumption (24), knocking tied to bearing failure (13), and outright engine failure with internal damage (12) — plus a steering issue causing power loss serious enough to be flagged at safety severity (12 reports). Oil consumption persisted into 2018 (32 reports) alongside stalling and failure (20) and random headlight failures (15), and continued through 2019, appearing in two separate complaint phrasings totaling 26 reports, alongside a forward collision avoidance system failure (14, safety-rated) and a brake system failure (9, also safety-rated) — the highest safety count of the five years at three. By 2020, oil consumption, knocking and misfires, and outright engine failure into limp mode remained the three leading complaints, with the year's total easing to 96.

None of these five years carries a recall beyond the single 2016 campaign, meaning most of this oil-consumption pattern would have been addressed, if at all, through warranty repair rather than a mandated fix. Given how consistently the complaint recurs across model years, an oil-consumption check and full service history review are especially worthwhile here — though these figures reflect owner-filed reports rather than a lab-measured failure rate, and newer years in any span like this simply accumulate fewer reports with less time on the road. A thorough pre-purchase inspection remains the best safeguard regardless of year.