This page covers 4 recalls, 13 owner complaints and EPA fuel economy for the 2018 Hyundai Ioniq.
136 MPGe combined
Large Cars
Fuel economy data from fueleconomy.gov (EPA / U.S. Dept. of Energy). Annual cost based on 15,000 mi/yr at 55% city driving and current fuel prices. MPG is U.S. gallons; L/100km converted. Ranges reflect the 2 tested variants for this model year.
Complaints for the 2018 Hyundai Ioniq are spread across a small number of reports, with the engine and powertrain drawing the most attention. On the powertrain side, owners describe rough gear transitions, particularly between first and second gear, along with clutch-related failures that produced jerking, sputtering, and sluggish or unresponsive acceleration. One owner reports a clutch actuator replacement was needed. Engine complaints include a separate account of a hole in the engine block accompanied by smoke entering the cabin. A couple of owners also describe electrical glitches: the instrument cluster going dark while driving, requiring a roadside restart to restore the display. The vehicle speed control complaints appear tied to the hesitation and acceleration lag owners associate with the transmission behavior rather than a distinct cruise-control system fault.
13
Total Complaints
2
Crash-Related
1
With Injuries
By System
The 2018 Hyundai Ioniq has 4 recalls, the most serious being a fire risk from the power relay assembly located beneath the rear seat, which can overheat and ignite the seat above it.
A prior repair attempt for this issue did not fully resolve the problem, and the overheating risk remains. On plug-in hybrid and electric variants, there is a separate electrical concern where an unstable ground connection can cause the vehicle to enter a reduced-power mode and then accelerate unexpectedly after the driver lifts off the accelerator, raising the risk of a crash. The fourth recall applies only to plug-in hybrid models sold in Canada, where the compliance label on certain vehicles lists incorrect weight ratings for the front and rear axles.
At a glance
What can fail
The Power Relay Assembly under the rear seat may overheat in certain 2017-2018 Ioniq HEV and PHEV vehicles.
What the fix does
Dealers will inspect and replace the main relay or Power Relay Assembly as needed at no cost.
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Complaints are owner-reported and reflect individual experiences, not confirmed defects. They are distinct from recalls. Data sourced from the national vehicle safety complaint database. See trending complaints →
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
A faulty electrical ground connection may cause the vehicle to enter fail-safe mode, reducing acceleration and power. While in fail-safe mode, the vehicle may continue accelerating even after you release the gas pedal.
What the fix does
Dealers will update the Electric Power Control Unit software and repair the ground wiring at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The Main Relay in the Power Relay Assembly may have loose or corroded electrical connections, causing higher electrical resistance and potential power delivery problems.
What the fix does
Dealers will inspect the Power Relay Assembly for damage. If undamaged, the main relay will be replaced. If damaged, the entire assembly will be replaced.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The weight rating label on your vehicle shows incorrect maximum weights for the front and rear axles. Overloading beyond these limits could cause tire failure or unsafe handling, increasing crash risk.
What the fix does
Hyundai will mail you a corrected label with installation instructions. You can install it yourself or have a Hyundai dealer install it for you.
Summarized — see the official notice for exact wording, dates, and contacts.
