GarageCalc What the data says
Engine accounts for about 56% of this year's Kia Optima complaints. That is a strong concentration, the kind that usually points to a specific known issue rather than general wear.
The 2013 model year contributes 52 complaints (19%). Older vehicles dominate, consistent with age-related wear rather than a new defect.
Complaints are down year over year, 388 to 272 (-30%), while the market overall rose about 2%. Year-over-year movement is the most useful signal here: a model's sales are roughly stable from one year to the next, so a sharp rise means the per-vehicle complaint rate genuinely moved, not just that the model is popular.
How to read this
Raw complaint totals track how many Kia Optimas are on the road as much as they track quality, so a high count on a best-seller is partly a volume story. Complaints are also self-reported: they capture what owners chose to file, not a controlled survey. Use these numbers to know where to look during a pre-purchase inspection and which recalls to check, not as a verdict on their own. Compare any car instantly in the Car Complaint Checker, or read the full 2026 study for the market-wide picture and methodology.
Frequently asked questions
Is the Kia Optima reliable?
Complaint counts alone cannot answer that, because they track how many are on the road as much as build quality. What the 2026 data shows: 272 NHTSA complaints so far (rank 44 of 765 models), -30% year over year, with engine the most-cited area. Treat it as a starting point and cross-check recalls and a pre-purchase inspection for the specific vehicle.
What is the most common Kia Optima complaint?
Engine: 153 of the 272 complaints filed in 2026 cite it (about 56%). That is a strong concentration, the kind that usually points to a specific known issue rather than general wear.
Which Kia Optima model year has the most complaints?
The 2013 model year, with 52 of this year's 272 complaints (about 19%). Older vehicles dominate, consistent with age-related wear rather than a new defect.
Source: NHTSA Office of Defects Investigation complaint database, complaints received 2026-01-01..2026-08-24, compared with 2025-01-01..2025-08-24 (same window). Counted once per complaint ID, vehicles only. Aggregated data is available under CC BY 4.0 with a link to GarageCalc.