AutoUtility currently tracks 13 official NHTSA owner defect complaints for the 2018 Hyundai Ioniq. Engine & Cooling issues are the most frequently reported category, appearing in 3 complaints (23.1% of submitted records). Among these NHTSA complaint records, 2 filings cite a crash, 1 reports one or more injuries.
Factual proportion of owner complaints categorized by automotive subsystem in NHTSA records
3 owner complaints submitted to NHTSA ODI for this subsystem.
3 owner complaints submitted to NHTSA ODI for this subsystem.
3 owner complaints submitted to NHTSA ODI for this subsystem.
2 owner complaints submitted to NHTSA ODI for this subsystem.
Formal engineering analyses and preliminary evaluations opened by the NHTSA Office of Defects Investigation
Representative defect filings submitted by owners to the NHTSA Office of Defects Investigation
"My 2018 Hyundai Ioniq Hybrid has a safety-critical transmission defect. The vehicle slips violently from 1st to 2nd gear, loses acceleration, and causes unpredictable hesitation. This creates a danger when merging onto highways or crossing intersections. Hyundai refused goodwill assistance, denied..."
"The contact owned a 2018 Hyundai Ioniq Hybrid. The contact stated while driving 75 MPH with her aunt in the front passenger's side seat, another vehicle suddenly merged into the contact's lane, causing the passenger's side of the vehicle to crash into the driver's side of the other vehicle. The..."
"The clutch failed and the clutch and I believe the clutch actuator had to be replaced. It was not available for inspection upon request. My safety and the risk of others were compromised by the constant jerking and sputtering, of the gears that took place during vehicle operation. My acceleration..."
"The car engine started to stall, the engine light came on and advised me to shut off engine then I pulled over and smoke immidiatley filled the cabin and outside the hood. My engine could have blown up. Had I not pulled over so quickly my car would have caught fire and I would have died. Yes the..."
"My lcd screen constantly goes black. A couple times the steering wheel locked the wipers and washer fluid went off at the same time. I had to hit the brakes and power the car on and off to reset it while making a turn. When having my window motor replaced for the SECOND time my dash where the speed..."
Reported defect complaint volume across sibling model years (2017–2026)
| Model Year | NHTSA Complaints | Crash Reports | Safety Recalls | Detailed Report |
|---|---|---|---|---|
| 2017 Hyundai Ioniq | 49 | 5 | 5 | View 2017 Problems → |
| 2018 Hyundai Ioniq Current Page | 13 | 2 | 3 | Current |
| 2019 Hyundai Ioniq | 22 | 6 | 2 | View 2019 Problems → |
| 2020 Hyundai Ioniq | 29 | 6 | 1 | View 2020 Problems → |
| 2021 Hyundai Ioniq | 0 | 0 | 0 | View 2021 Problems → |
| 2022 Hyundai Ioniq | 21 | 2 | 0 | View 2022 Problems → |
| 2023 Hyundai Ioniq | 0 | 0 | 0 | View 2023 Problems → |
| 2024 Hyundai Ioniq | 0 | 0 | 0 | View 2024 Problems → |
| 2025 Hyundai Ioniq | 0 | 0 | 0 | View 2025 Problems → |
| 2026 Hyundai Ioniq | 0 | 0 | 0 | View 2026 Problems → |
Complete distribution of consumer defect reports across all 9 granular NHTSA system and subsystem classifications
| Vehicle Component / System | Total Complaints | Crash Reports | Fire Reports | Injury Entries | Fatality Entries |
|---|---|---|---|---|---|
| Powertrain NHTSA category: POWER TRAIN | 3 | 1 | 0 | 0 | 0 |
| Engine NHTSA category: ENGINE | 2 | 0 | 0 | 0 | 0 |
| Vehicle Speed Control NHTSA category: VEHICLE SPEED CONTROL | 2 | 0 | 0 | 0 | 0 |
| Air Bags NHTSA category: AIR BAGS | 1 | 1 | 0 | 2 | 0 |
| ELECTRICAL SYSTEM,ENGINE | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,UNKNOWN OR OTHER | 1 | 0 | 0 | 0 | 0 |
| STEERING,ELECTRICAL SYSTEM,VISIBILITY/WIPER | 1 | 0 | 0 | 0 | 0 |
| Other / Uncategorized NHTSA category: UNKNOWN OR OTHER | 1 | 0 | 0 | 0 | 0 |
| UNKNOWN OR OTHER,SERVICE BRAKES | 1 | 0 | 0 | 0 | 0 |
Cross-reference safety recalls, crash test safety ratings, and EPA fuel economy for this model year
Key performance indicators, EPA fuel economy specs, powertrain variants, and summary ratings.
Official recall campaigns, safety defect descriptions, and manufacturer free remedy instructions.
NHTSA 5-Star NCAP crash test results, driver assistance systems, and rollover resistance ratings.
EPA fuel economy ratings, electric range, and annual energy cost benchmarks.
Direct, deterministic answers synthesized from verified United States government databases for the 2018 Hyundai Ioniq
In official NHTSA consumer records, the most frequently cited issue area for the 2018 Hyundai Ioniq is Engine & Cooling, appearing in 3 records (23.1% of submitted filings).
Secondary reported categories include Powertrain & Transmission (3) and Electrical System (3).
AutoUtility does not issue subjective reliability scores or commercial ratings. In official United States government records, NHTSA tracks 13 consumer defect complaints and 3 safety recall campaigns for the 2018 Hyundai Ioniq.
Reviewing documented component complaint distributions, recall remedy notices, and active federal investigations provides an objective, evidence-based view of the vehicle's historical safety and defect record.
Among consumer complaint records on file with NHTSA for the 2018 Hyundai Ioniq, 2 filings cite a crash, 0 cite smoke or fire, and 1 report one or more injuries.
Incident entries represent consumer descriptions at the time of submission to federal authorities and do not establish mechanical causation or legal liability.
NHTSA ODI records list 1 formal defect investigation involving the 2018 Hyundai Ioniq (all closed).
Federal defect investigations are formal engineering evaluations opened when safety defect trends emerge, and do not by themselves establish a confirmed defect or mandatory recall.
The complaint records on this page are retrieved directly from the NHTSA Office of Defects Investigation (ODI) public database under 49 CFR Part 576.
Local Production Store Compiled: August 2026 • Deterministic Audited Dataset • Zero Dynamic External API Runtime Latency.