2017 Hyundai Sonata vs 2017 Kia Optima
Two midsize cars, compared on what actually matters when you're buying used:
what breaks, when it breaks, and what it costs you.
2017 Hyundai
Sonata
5/10
A comfortable, well-equipped mid-size sedan crippled by a well-documented engine that can spontaneously knock, burn oil, or catch fire — buy only with a clean engine inspection and ideally the 1.6T instead.
VS
2017 Kia
Optima
5/10
Great value on paper, but the Theta II engine's rod bearing lottery makes this a car you buy with a lawyer's eye, not a shopper's.
Dead heat: both score 5/10. The tiebreaker is which specific car you find.
By the numbers
Green is the better number — higher on every score, lower on failures, complaints and recalls.
| Hyundai Sonata |
Kia Optima |
| Known failure points | 6 | 5 |
| NHTSA complaints | 761 | 254 |
| Safety recalls | 3 | 3 |
| Service bulletins | 12 | 12 |
| Reliability | 42 | 42 |
| Cheap to own | 38 | 45 |
| Fun factor | 38 | 48 |
| Holds value | 40 | 38 |
| Enthusiast cred | 22 | 25 |
The most expensive thing that goes wrong
2017 Hyundai Sonata
Theta II 2.4L GDI rod bearing knock / catastrophic oil consumption (the class-action engine)
$4,000–$7,00040k–90k mi
2017 Kia Optima
Catastrophic engine seizure from unresolved oil consumption/rod knock (the failure mode owners report on forums and to NHTSA)
$5,000–$8,50080k–120k mi
If you buy one, buy this one
✅ 2017 Hyundai Sonata
2017 Sonata Eco with the 1.6T Gamma engine and 7-speed dual-clutch — sidesteps the worst Theta II drama, gets ~32+ mpg combined, and still has a mid-level tech package.
✅ 2017 Kia Optima
2017 Optima SXL 2.0T with full documented service history, clean UBPI (used bearing/piston inspection) or dealer oil consumption test, and confirmed enrollment in the Theta II engine settlement — loaded, quicker, and the least likely to burn oil catastrophically.
Narrowed it down? Get the full report
This comparison is model-level.
Milo's report goes car-level — the one you're actually looking at:
- A line-by-line negotiation script
- The pre-purchase inspection checklist
- VIN-specific open recalls
- What it's really worth right now
- Your next 15,000 miles, forecast
- Hidden features & money-savers
Run my free report →
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Scores and findings blend documented NHTSA recalls and complaints with
patterns synthesized from owner communities. Always inspect the specific vehicle and
verify open recalls by VIN before buying.