Is the 2021 Hyundai SONATA reliable?

The 2021 Hyundai SONATA has 167 complaints filed with NHTSA (0.3x the segment average). Our reliability verdict: above-average. Most common issue: ENGINE problems.

What are common problems with the 2021 Hyundai SONATA?

Top problems: ENGINE (33 complaints, avg repair $500); OTHER (30 complaints, avg repair $500); FUEL SYSTEM (25 complaints, avg repair $500). Issues typically appear around 50K miles.

Are there any recalls on the 2021 Hyundai SONATA?

Yes, there are 4 recall(s): FUEL SYSTEM, GASOLINE:DELIVERY:HOSES, LINES/PIPING, AND FITTINGS, VISIBILITY:WINDSHIELD, POWER TRAIN:AUTOMATIC TRANSMISSION, FUEL SYSTEM, GASOLINE. Contact any Hyundai dealer to verify if recalls have been completed on your specific vehicle.

How much does it cost to fuel a 2021 Hyundai SONATA?

The 2021 Hyundai SONATA gets 30 MPG combined. At current US average gas prices, driving 12,000 miles per year costs roughly $1600. See the interactive fuel cost calculator on this page for state-specific pricing.

Is the 2021 Hyundai SONATA often stolen?

The Hyundai SONATA was the #3 most-stolen vehicle in the United States in 2025 with approximately 17,687 thefts (NICB Hot Wheels data). Theft risk tier: very-high. Pre-2022 models are affected by the Kia Boys challenge — verify your VIN has the manufacturer security update.

How much does it cost to insure a 2021 Hyundai SONATA?

Estimated US average full-coverage insurance for the 2021 Hyundai SONATA is approximately $2,030/year (sedan-midsize class). Actual quotes vary heavily by state, driver age, driving record, and credit — see the interactive insurance estimator on this page for state-specific pricing.

2021 Hyundai SONATA

Problems, Recalls & Reliability Report

Above Average

Quick Summary

The 2021 Hyundai SONATA has 167 owner complaints filed with NHTSA — that's 0.3x the segment average of 540. The most common issue is engine problems (20% of all complaints), specifically: the contact owns a 2021 hyundai sonata. the contact stated that while the vehicle was at an independent mechanic for an oil change, the mechanic diagnosed the vehicle with transmission fluid leaking from the engine. the mechanic informed the contact that the transmission fluid leakage was flammable.. There are 4 recalls issued for this model year.

10 crash reports 24 injuries

167

Total Complaints

Recalls Issued

5/5

Safety Stars

0.3x

vs Segment Avg

Known Problems(top 5 of 8)

ENGINE

33 complaints

20%

• The contact owns a 2021 Hyundai Sonata. The contact stated that while the vehicle was at an independent mechanic for an oil change, the mechanic diagnosed the vehicle with transmission fluid leaking from the engine. The mechanic informed the contact that the transmission fluid leakage was flammable.
• Since we purchased this brand new vehicle, we have had in the dealership service department at a minimum of 5 times for same issue. The vehicle accelerates while stopped at a light so we have to put it in neutral to keep it from accelerating. Once we take out of Neutral and release the break, the ve
• The contact owns a 2021 Hyundai Sonata. The contact stated while driving 65 MPH and attempting to accelerate, the vehicle failed to respond with the check engine warning light illuminated. The contact also heard a knocking sound coming from the vehicle. The contact pulled over on the side of the roa

Typical onset: 50K miles Est. repair: $500💥 1 crashes

“The contact owns a 2021 Hyundai Sonata. The contact stated that while the vehicle was at an independent mechanic for an oil change, the mechanic diagnosed the vehicle with transmission fluid leaking from the engine. The mechanic informed the contact that the transmission fluid leakage was flammable.”

— NHTSA complaint filing

When Problems Appear on the 2021 Hyundai SONATA

Based on 25 owner complaints that included an odometer reading. Median mileage at time of complaint: 28K miles. Most complaints cluster in the 0-30K miles range.

Overall complaint distribution by mileage

0-30K

30-60K

60-100K

100-150K

150-200K

200K+

ENGINE

In line with typicalmedian 46K mi · 6 reports

0-30K

30-60K

60-100K

100-150K

150-200K

200K+

TRANSMISSION

In line with typicalmedian 22K mi · 6 reports

0-30K

30-60K

60-100K

100-150K

150-200K

200K+

FUEL SYSTEM

High-mileage issuemedian 81K mi · 6 reports

0-30K

30-60K

60-100K

100-150K

150-200K

200K+

Mileage figures are self-reported by owners in NHTSA complaint filings. Peak bucket = the mileage range with the most complaints for that component; it reflects when owners noticed and reported problems, not necessarily when the fault first occurred.

Recalls (4)

FUEL SYSTEM, GASOLINE:DELIVERY:HOSES, LINES/PIPING, AND FITTINGS09/07/2021

Hyundai Motor America (Hyundai) is recalling certain 2021-2022 Santa Fe and Sonata vehicles equipped with 2.5L turbocharged engines. Fuel may leak at the pipe connection between the high-pressure fuel pump and fuel rail.

Risk: A fuel leak increases the risk of a fire.

Fix: Dealers will inspect and tighten, or replace the fuel pipe as necessary, free of charge. Owner notification letters were mailed on September 3, 2021. Owners may contact Hyundai customer service at 1-855-371-9460. Hyundai's number for this recall is 207.

Very high theft risk

#3 most stolen in 2025

The Hyundai SONATA was the #3 most-stolen vehicle in the United States in 2025, with approximately 17,687 thefts reported to law enforcement.

Kia Boys / TikTok theft vulnerabilityModel years 2010-2021 Hyundai and Kia vehicles without engine immobilizers were widely targeted starting in 2022 after a viral TikTok exploit. If you own this vehicle, verify it has an ignition immobilizer or install a security upgrade. Hyundai and Kia both offered free software updates and steering-wheel-lock programs for affected models.

Recommended protection: engine immobilizer verification, steering wheel lock, GPS tracker, and comprehensive insurance coverage. Higher theft risk usually translates to higher comprehensive-coverage insurance premiums.

Source: NICB Hot Wheels 2025 report + HLDI theft loss studies. Model-year ranking; not all years of this model have identical risk.

Fuel Cost Calculator for 2021 Hyundai SONATA

Live EIA prices

Annual miles driven: 12,000

Your state (affects local gasoline price)

Per year

$1,600

Per month

$133

Per mile

13.3¢

MPG

City driving (worst-case MPG)

$2,087/yr

Highway driving (best-case MPG)

$1,263/yr

Based on EPA fuel-economy ratings and EIA weekly retail prices (2026-07-20). Real-world cost varies with driving style, trim/engine, terrain, and traffic.

5-Year Gas Price History

EIA weekly retail data · 2021 → today

Show:

Current

$4.00

5-year low

$2.78

5-year high

$5.01

Since 2021

+27%

Source: US Energy Information Administration weekly retail gasoline prices.

Estimated Insurance Cost for 2021 Hyundai SONATA

Estimate only, not a quote. Modeled from NAIC + HLDI averages for a hypothetical 35-year-old driver with clean record + full coverage. Your actual quote depends heavily on your age, driving history, credit, ZIP code, and insurer.

Your state (affects local premium average)

Full coverage / year

$2,030

Full coverage / month

$169

Liability only / year

$574

vs US avg

+21%

How this estimate is calculated

US base full-coverage premium$1674

× state (US)1.00x

× vehicle class (sedan-midsize)0.96x

× theft risk1.28x

× safety rating0.94x

× vehicle age1.05x

= Full coverage estimate$2030

Coverage assumed: 100/300/100 liability + comprehensive/collision, $500 deductibles. Data sources: NAIC 2024 + HLDI loss studies.

Maintenance & Warranty

Recommended Hyundai SONATA Service Intervals

Oil change

8K mi / 12 mo

Tire rotation

8K mi

Brake fluid

24 months

Transmission fluid

60K mi

Engine coolant

60K mi

Spark plugs

90K mi

Cabin air filter

15K mi

Engine air filter

30K mi

Differential (AWD/4WD)

60K mi

Turbo engines (1.6T, 2.0T) need premium fuel and more frequent oil (some owners service at 5,000 miles).

"Severe service" conditions (heavy towing, extreme temps, city stop-and-go) typically halve these intervals. Always consult your vehicle's owner's manual for the authoritative schedule.

Hyundai New-Vehicle Warranty Coverage

Bumper-to-bumper (basic)

5 yr / 60K mi

Powertrain

10 yr / 100K mi

Hybrid/EV battery

10 yr / 100K mi

Corrosion (rust perforation)

7 yr / unlimited mi

Roadside assistance

5 yr / unlimited mi

10 years/100K powertrain warranty is transferable only to first purchaser after initial owner

These are the terms for a new Hyundai. If you're buying a used 2021 SONATA, remaining coverage is usually pro-rated from the vehicle's original in-service date. Not all coverage transfers between owners — check with a Hyundai dealer for VIN-specific remaining warranty.

Estimated Repair Costs

ENGINE(~50K mi)

$500

OTHER(~50K mi)

$500

FUEL SYSTEM(~50K mi)

$500

TRANSMISSION(~50K mi)

$500

ELECTRICAL(~50K mi)

$500

Estimates based on average reported repair costs. Actual costs vary by location, shop, and severity.

🔍 Pre-Purchase Inspection Checklist

Based on 167 owner complaints for this specific year, here's what to check or ask about:

☐
ENGINE: The contact owns a 2021 Hyundai Sonata. The contact stated that while the vehicle was at an independent mechanic for an oil change, the mechanic diagnosed the vehicle with transmission fluid leaking from the engine. The mechanic informed the contact that the transmission fluid leakage was flammable.
Typically appears around 50K miles. Repair cost ~$500
☐
OTHER: SEEMS TO BE AN ISSUE WITH THE WIRELESS APPLE CAR PLAY. REGARDLESS IF THE VEHICLE IS IN MOTION OR NOT IT LOSES CONNECTIVITY. WHILE DRIVING THIS CAUSE YOU TO TAKE YOUR EYES OFF THE ROAD AS MESSAGES APPEAR ON THEIR INFOTAINMENT SYSTEM. CALLS ARE DROPPED, NAVIGATION STOPS SO WHILE YOU ARE LOOKING AT
Typically appears around 50K miles. Repair cost ~$500
☐
FUEL SYSTEM: The contact owns a 2021 Hyundai Sonata. The contact stated while driving at various speeds, he smelled an abnormally strong fuel odor inside the vehicle. There were no warning lights illuminated. The vehicle was taken to the dealer who informed the contact that they could duplicate the failure. The
Typically appears around 50K miles. Repair cost ~$500
☐
TRANSMISSION: My transmission went bad on my new car. Didn’t have my car for 4 month August 12 2021
Typically appears around 50K miles. Repair cost ~$500
☐
RECALLS: Verify all 4 recalls have been completed — free at any Hyundai dealer
☐
General: Get a pre-purchase inspection from an independent mechanic ($100-$200)