Research · Midsize Cars · 2 NHTSA variants

2018 Hyundai Ioniq Plug-in HybridRecalls, problems, MPG & safety

NHTSA lists 1 safety recall and 4 owner complaints for the 2018 Hyundai Ioniq Plug-in Hybrid. Most complaints involve structure (1) and visibility/wiper (1). The EPA rates it 52 mpg combined.

Combined MPG
52mpg
EPA · 1 version
NHTSA overall
—
Not rated by NCAP
Safety recalls
1campaigns
Latest Jun 2022
Owner complaints
4
Top: structure
Fuel cost / yr
$1,150est.
EPA estimate, best version
01 —Recalls

Safety recalls

1 NHTSA campaign · applies to some vehicles, check your VIN

Hybrid propulsion system: inverter

Free remedy

Hyundai Motor America (Hyundai) is recalling certain 2017-2018 Ioniq HEV and Ionic PHV vehicles previously recalled under recall number 18V-704. The Power Relay Assembly (PRA) located underneath the rear seat may overheat.

Hybrid propulsion systemReported Jun 28, 2022NHTSA 22V459000
Data from NHTSA Recalls API · synced Nov 12, 2026 · All recall detailsNHTSA vehicle page
02 —Complaints

Owner complaints by component

4 complaints filed with NHTSA · Nov 2021 – May 2026
  1. Structure1
  2. Visibility/wiper1
  3. Engine and engine cooling1
  4. Other / unknown1

Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.

By model year

Complaints for each Ioniq Plug-in Hybrid model year we’ve synced.

View as table
Model yearNHTSA complaints
20184
201911
20206
202118
20223
Crashes reported
0
Fires reported
0
Injuries reported
0
Deaths reported
0
Data from NHTSA Complaints API · synced Nov 12, 2026NHTSA vehicle page
03 —Common problems

What owners report most

Verbatim excerpts from NHTSA complaints, by component

Structure

1 report
“The contact owns a 2018 Hyundai Ioniq Hybrid. The contact stated that upon inspection, it was discovered that both the passenger’s side front and rear carpets had become soaked with water and condensation from the operation of the air conditioning unit. The contact was also concerned that mold was present due to the failure. The local dealer was contacted and a service appointment was scheduled. The manufacturer was not yet notified. The failure mileage was 12,000.”
Owner complaint to NHTSAFiled Jul 5, 2022StructureODI 11472321

Visibility/wiper

1 report
“Sunglass holder would randomly come down and block rear view mirror completely. Unable to see the back.”
Owner complaint to NHTSAFiled Jan 14, 2022Visibility/wiperODI 11447542

Engine and engine cooling

1 report
“I have put around 31K miles in my car. Day before yesterday ( Nov-2 ) when I was driving back home from work, suddenly I heard a noise. I pulled over and stopped the car. when I got down and checked, I noticed exhaust system or something similar to that fell off and touching the road. I have seen similar issues posted in Hyundai Ioniq forums https://www.ioniqforum.com/threads/very-dissapointed.37027/ https://www.ioniqforum.com/threads/first-issue-exhaust-fell-off-at-21k-miles-2019-phev.35092/ I will attach few pictures that I took during this incident.”
Owner complaint to NHTSAFiled Nov 5, 2021Engine and engine coolingODI 11439532
Data from NHTSA Complaints API (owner reports, unverified) · synced Nov 12, 2026
04 —Key specs

Engines, transmissions & drive

1 version rated by the EPA
EPA class
Midsize Cars
Engines
1.6L 4-cyl plug-in hybrid
Transmissions
Automatic (AM6)
Drive
Front-Wheel Drive
Fuel
Regular Gasoline
EV range
630 mi (EPA)

Towing, payload and dimensions aren’t in the EPA or NHTSA data, so we don’t list them.

Data from EPA fueleconomy.gov · synced Nov 12, 2026EPA listing
05 —Fuel economy

EPA fuel economy by version

City / highway / combined, annual fuel cost and CO₂
EPA
VersionCityHwyComb.Fuel / yrCO₂ g/mi
Ioniq Plug-in Hybrid
Auto (AM6), 4 cyl, 1.6 L · Front-Wheel Drive
535252$1,15075
Data from EPA fueleconomy.gov · synced Nov 12, 2026 · Fuel cost is EPA’s annual estimate (15,000 mi, 55% city)
06 —Safety

NHTSA 5-Star Safety Ratings

1 tested variant
NHTSA has not published 5-Star Safety Ratings for the 2018 Hyundai Ioniq Plug-in Hybrid as of Nov 12, 2026.
Data from NHTSA NCAP Safety Ratings API · synced Nov 12, 2026Vehicle 12672
07 —Maintenance

Maintenance basics

General guidance, not the OEM schedule. Check your owner’s manual.
General guidance
ItemMilesTimeNote
Engine oil & filter5,000–10,000 mi6–12 monthsFollow the oil-life monitor if fitted
Tire rotation5,000–7,500 miEvery oil changeCheck pressure monthly
Engine air filter15,000–30,000 mi1–2 yearsSooner in dusty areas
Cabin air filter15,000–25,000 mi1–2 years
Brake fluid—2–3 yearsAbsorbs moisture over time
Coolant60,000–100,000 mi5–10 yearsLong-life coolants last longer
Spark plugs60,000–100,000 mi—Iridium/platinum plugs at the long end
12V battery—3–5 yearsHeat shortens battery life
  • Engine oil & filter5,000–10,000 mi
    6–12 months
  • Tire rotation5,000–7,500 mi
    Every oil change
  • Engine air filter15,000–30,000 mi
    1–2 years
  • Cabin air filter15,000–25,000 mi
    1–2 years
  • Brake fluid—
    2–3 years
  • Coolant60,000–100,000 mi
    5–10 years
  • Spark plugs60,000–100,000 mi
    —
  • 12V battery—
    3–5 years
Typical intervals for modern cars. Severe service (towing, short trips, extreme heat or cold) shortens them.
09 —FAQ

2018 Ioniq Plug-in Hybrid questions

How many recalls does the 2018 Hyundai Ioniq Plug-in Hybrid have?

1 safety recall as of Nov 12, 2026, according to NHTSA. Recall repairs are free at a dealer. Check your VIN to see whether your car is included and whether the repair was done.

What are the most common 2018 Hyundai Ioniq Plug-in Hybrid problems?

Owners filed 4 complaints with NHTSA. The most-cited components are structure (1), visibility/wiper (1), engine and engine cooling (1). Complaints are unverified owner reports and aren't adjusted for how many cars were sold.

What MPG does the 2018 Hyundai Ioniq Plug-in Hybrid get?

The EPA rates the 2018 Hyundai Ioniq Plug-in Hybrid at 52 mpg combined, depending on engine and drivetrain (1 version rated).

Data from NHTSA & EPA · synced Nov 12, 2026