YearToAvoid

2021 Hyundai Sonata Hybrid Problems, Recalls & Reliability

Verdict

Caution

Complaint Index

71/100

#5 most-complained of 15 Sonata Hybrid years

The 2021 Hyundai Sonata Hybrid has a Complaint Index of 71, ranking 5th worst among 15 model years, earning a Caution verdict. Electrical System (45% of complaints) and Engine (44%) issues dominate, though there are 0 recalls on file.

Complaints
55
Recalls
0
Crashes / fires
1 / 0
Injuries / deaths
2 / 0
NHTSA overall rating
5 / 5 ★
EPA combined MPG
49.5
47.5 city / 52.5 hwy

Top 2021 Hyundai Sonata Hybrid problems

NHTSA owner complaints by component group. Groups with 15+ complaints have their own page.

  1. Electrical System25 (45%)
  2. Engine24 (44%)
  3. Other7 (13%)
  4. Fuel System5 (9%)
  5. Transmission & Powertrain4 (7%)
  6. Collision Avoidance & Cameras3 (5%)
  7. Structure & Body1 (2%)
  8. Suspension, Wheels & Tires1 (2%)
  9. Visibility & Wipers1 (2%)

What owners report

  • Dashboard warning lights flash randomly while driving at highway speed, sometimes with the infotainment screen going black.
  • Owners report the engine overheating alert triggers on the highway with no other warning lights, forcing a pullover.
  • Some describe loud alarms, smoke, and an overheating warning while decelerating on an exit ramp.
  • The cabin heater blows cold air despite the coolant being topped off, even after dealer visits.
  • The 12V battery dies randomly and unpredictably, sometimes with the car shutting off while parked or being driven.
  • The shift selector has been reported stuck in Drive or locked in place, leaving the vehicle inoperable.
2021 Hyundai Sonata Hybrid complaints: complaints filed per month7Oct 2021Aug 2023Feb 2024Jul 2024Dec 2024Jun 2025Jun 2026
71 complaints filed with NHTSA from Oct 2021 to Sep 2026; peak Dec 2023 (7).

2021 Hyundai Sonata Hybrid recalls

No safety recalls on record for this model year.

2021 Hyundai Sonata Hybrid fuel economy and fuel cost

City
47.5 MPG
Highway
52.5 MPG
Combined
49.5 MPG
Annual fuel cost (EPA)
$1,325
15,000 mi/yr
Fuel
Regular
Current regular gas
$4.32/gal
national avg.

EPA figures; median across configurations of this model year. Estimate your own cost with the fuel cost calculator.

2021 compared with other Sonata Hybrid years

Complaint Index by model year (0 = fewest issues, 100 = most)0255075100’11’12’13’14’15’16’17’18’19’20’21’22’23’24’25
Complaint Index: 0 = fewest issues, 100 = most, relative to other years of this model. Avoid Caution Good Best
YearVerdictIndexComplaintsRecallsMPG
2019No verdict04041.5
2020Best2116149.5
2021Caution7155049.5
2022Good2919049.5
2023Good4315049.5

All Hyundai Sonata Hybrid years: best and worst →

Frequently asked questions

Is the 2021 Hyundai Sonata Hybrid reliable?
Based on NHTSA owner complaints and recalls, the 2021 Sonata Hybrid has a Complaint Index of 71 and ranks 5th worst out of 15 model years, giving it a Caution verdict relative to other Sonata Hybrid years.
What are the most common problems with the 2021 Sonata Hybrid?
NHTSA complaints show Electrical System issues make up 45% of complaints and Engine issues make up 44%, including reports of overheating warnings and dashboard lights flashing while driving.
Does the 2021 Sonata Hybrid have any recalls?
NHTSA lists 0 recalls for the 2021 Sonata Hybrid, and there are no do-not-drive recalls.
At what mileage do 2021 Sonata Hybrid problems usually appear?
The median mileage at failure across reported complaints is 28,273.5 miles, with Electrical System issues showing up at a median of 24,000 miles and Engine issues at 32,547 miles.
How does the 2021 Sonata Hybrid compare to other Sonata Hybrid years?
Its Complaint Index of 71 is worse than 2018 (7), 2020 (21), 2022 (29), and 2024 (14), but better than the worst years like 2012 (93) and 2013 (100).

Sources: NHTSA Office of Defects Investigation complaint and recall databases; U.S. EPA fuel economy data; NHTSA 5-Star Safety Ratings. Complaints are unverified owner reports.

Data updated Sep 24, 2026. Read the methodology and data sources. The Complaint Index is based on NHTSA owner complaints and recalls; it is not a reliability rating.