2018 Hyundai Sonata: what breaks, and at what mileage
What breaks on the 2018 Hyundai Sonata
On the 2018 Hyundai Sonata, the failure owners report most often is other engine problem, and the reports cluster around 42,500 miles. The earliest to appear is headlight failure or clouding, reported by a median of 1,900 miles. Overall it scores 79 out of 100, severe risk for a 2018.
Severe risk for a 2018 — 65th riskiest of the 251 2018 vehicles we can rate. 550 owner reports; fleet size estimated from this year's own recall paperwork.
What breaks on the 2018 Hyundai Sonata
Owners have reported 62 named failure modes on the 2018 Hyundai Sonata, and the three most-reported carry 31% of everything filed, which is an unusually even spread for one model year.
Other engine problem leads with 85 reports, about 2.4 per 1,000 vehicles and with the middle half of reports between 8k to 72,500 miles.
Excessive oil consumption follows with 54 reports, median 80,000 miles. 1 of those report mention a fire.
Other electrical problem follows with 31 reports, usually reported between 8k to 80,000 miles. 3 of those reports mention a fire.
By system, the reports fall mostly into engine (204), electrical (75) and adas (36).
The mileage the reports cluster at
202 of the reports on the 2018 Hyundai Sonata came with an odometer reading, and half of those were filed before 20,000 miles.
Cumulatively, 70% by 50,000 miles, 87% by 100,000 miles and 96% by 150,000 miles of the dated reports had been filed, with 1 filed above the top of the chart.
The busiest stretch is between 0 and 10,000 miles, which alone holds 35% of the dated reports.
64% of the dated reports were filed below 36,000 miles, which is early enough that a fair number of these cars were still under a factory warranty when the owner complained.
In the order they tend to show up: headlight failure or clouding around 2k, other speed control problem around 9k, other brake problem around 9k and wiring harness or short circuit around 11k.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
Showing the 12 most-reported failure modes of 62. The full list is in the table below.
How reports accumulate
Every report with an odometer reading, cumulative, from 0 to 200,000 miles. A further 1 report came in above that, which is why the line stops short of the top. A curve that climbs early is a car with early problems, whatever its total.
- Line share of reports filed by that mileage
- Dashed the median reported mileage
How bad it is when it goes
Across the named modes, 22 mention a crash, 18 a fire and 16 an injury. Those are the words owners used in their own complaints, and NHTSA does not verify them, but they are the closest thing in this data to a measure of what a failure actually did.
The average severity weight across every report on this year is 4.15, where a stalled engine or a failed airbag weighs many times more than a rattling trim panel, and a figure this high means the reports are dominated by failures with safety consequences rather than annoyances. The weighting is set out in full on the methodology page.
What the top failures cost to put right, as editorial estimates for an independent US shop rather than figures from NHTSA: other engine problem at $300–$4,000, excessive oil consumption at $900–$6,500, other electrical problem at $250–$2,000 and no-start or intermittent start failure at $200–$1,800. Dealer labour, a seized bolt or a part that is no longer made can push any of these past the top of its range.
43% of the reports on this year sit in the engine, transmission, drivetrain or cooling systems — the four where a repair bill is usually four figures.
Every reported failure mode
| Failure mode | System | Reports | With reading | 25th | Median | 75th | Per 1,000 | Typical repair | Severity |
|---|---|---|---|---|---|---|---|---|---|
| Other engine problem | engine | 85 | 33 | 8k | 41k | 72k | 2.4 | $300–$4,000 | High |
| Excessive oil consumption | engine | 54 | 6 | — | 78k | — | 1.6 | $900–$6,500 | High |
| Other electrical problem | electrical | 31 | 8 | 8k | 35k | 80k | 0.9 | $250–$2,000 | Moderate |
| No-start or intermittent start failure | engine | 25 | 15 | 10k | 24k | 50k | 0.7 | $200–$1,800 | Moderate |
| Wiring harness or short circuit | electrical | 23 | 21 | 5k | 11k | 15k | 0.7 | $400–$3,500 | High |
| Other powertrain problem | transmission | 23 | 10 | 11k | 42k | 67k | 0.7 | $400–$4,500 | High |
| Other body or interior problem | body | 18 | 2 | — | 29k | — | 0.5 | $200–$2,000 | Moderate |
| Oil leak | engine | 14 | 2 | — | 51k | — | 0.4 | $250–$2,200 | Moderate |
| Other speed control problem | adas | 14 | 10 | 5k | 9k | 17k | 0.4 | $250–$2,000 | Critical |
| Other fuel system problem | fuel | 13 | 4 | — | 137k | — | 0.4 | $300–$2,200 | High |
| Other brake problem | brakes | 13 | 8 | 7k | 9k | 20k | 0.4 | $300–$1,800 | High |
| Headlight failure or clouding | lighting | 12 | 10 | 91 | 2k | 2k | 0.3 | $150–$1,800 | Moderate |
| Control module (ECM/PCM/BCM) failure | electrical | 11 | 1 | — | 20k | — | 0.3 | $700–$3,000 | High |
| Cruise control failure | adas | 11 | 8 | 7k | 18k | 20k | 0.3 | $200–$1,400 | High |
| ABS module or sensor failure | brakes | 10 | 5 | — | 157k | — | 0.3 | $500–$2,400 | High |
| Other lighting problem | lighting | 10 | 7 | — | 286 | — | 0.3 | $120–$1,200 | Moderate |
| Engine knock or bearing noise | engine | 9 | 1 | — | 3k | — | 0.3 | $2,500–$9,000 | High |
| Seat belt or retractor failure | airbag | 9 | 5 | — | 17k | — | 0.3 | $200–$900 | High |
| Other steering problem | steering | 8 | 1 | — | 41k | — | 0.2 | $350–$2,400 | High |
| Fuel pump failure | fuel | 7 | 0 | — | — | — | 0.2 | $600–$2,600 | High |
| Software fault or failed update | software | 7 | 5 | — | 14k | — | 0.2 | $0–$600 | Moderate |
| Other driver assistance problem | adas | 7 | 2 | — | 26k | — | 0.2 | $250–$1,800 | High |
| Misfire or rough idle | engine | 6 | 4 | — | 33k | — | 0.2 | $250–$1,600 | Moderate |
| Parking brake failure | brakes | 6 | 1 | — | 4k | — | 0.2 | $250–$1,300 | Moderate |
| Alternator or charging system failure | electrical | 5 | 0 | — | — | — | 0.1 | $450–$1,600 | High |
| Paint peeling or clear coat failure | body | 5 | 0 | — | — | — | 0.1 | $600–$6,000 | Low |
| Liftgate, tailgate or trunk failure | body | 5 | 3 | — | 28k | — | 0.1 | $250–$1,500 | Moderate |
| Tail light, brake light or signal failure | lighting | 5 | 0 | — | — | — | 0.1 | $100–$900 | Moderate |
| Ignition switch, key fob or immobilizer failure | electrical | 4 | 4 | — | 57k | — | 0.1 | $250–$1,500 | High |
| Airbag failed to deploy in a crash | airbag | 4 | 4 | — | 86k | — | 0.1 | $1,000–$5,000 | Critical |
| Lane keep or steering assist fault | adas | 4 | 1 | — | 1k | — | 0.1 | $200–$1,600 | High |
| Steering rack, gear or tie rod failure | steering | 4 | 1 | — | 60k | — | 0.1 | $700–$2,600 | High |
| Complete engine failure or seizure | engine | 3 | 0 | — | — | — | 0.1 | $4,500–$12,000 | Critical |
| Head gasket failure | engine | 3 | 0 | — | — | — | 0.1 | $1,400–$4,000 | Critical |
| CV axle or driveshaft failure | drivetrain | 3 | 2 | — | 87k | — | 0.1 | $450–$2,200 | High |
| Alignment fault and uneven tire wear | suspension | 3 | 0 | — | — | — | 0.1 | $150–$1,200 | Moderate |
| Sunroof failure or glass breakage | body | 3 | 1 | — | 72k | — | 0.1 | $700–$4,500 | High |
| Other wheel or tire problem | wheels | 3 | 1 | — | 28k | — | 0.1 | $200–$1,500 | High |
| Other visibility problem | glass | 3 | 1 | — | 125k | — | 0.1 | $150–$1,400 | Moderate |
| Piston, ring or cylinder wall damage | engine | 2 | 0 | — | — | — | 0.1 | $3,000–$9,500 | Critical |
| Overheating | cooling | 2 | 0 | — | — | — | 0.1 | $400–$3,500 | High |
| Steering column or shaft failure | steering | 2 | 1 | — | 22k | — | 0.1 | $600–$2,500 | Critical |
| Control arm, ball joint or bushing failure | suspension | 2 | 1 | — | 300 | — | 0.1 | $400–$2,200 | High |
| Catalytic converter failure | emissions | 2 | 0 | — | — | — | 0.1 | $900–$3,500 | Moderate |
| Timing chain, belt or tensioner failure | engine | 1 | 0 | — | — | — | 0.0 | $1,200–$4,500 | Critical |
| Stalling while driving | engine | 1 | 0 | — | — | — | 0.0 | $300–$2,500 | Critical |
| Turbocharger or supercharger failure | engine | 1 | 0 | — | — | — | 0.0 | $1,500–$4,500 | High |
| Transmission will not engage a gear | transmission | 1 | 0 | — | — | — | 0.0 | $1,500–$6,000 | Critical |
| Complete transmission failure | transmission | 1 | 0 | — | — | — | 0.0 | $2,800–$8,000 | Critical |
| Shifter, linkage or stuck-in-park failure | transmission | 1 | 0 | — | — | — | 0.0 | $250–$1,400 | High |
| Fuel tank, filler or EVAP failure | fuel | 1 | 0 | — | — | — | 0.0 | $250–$1,800 | Moderate |
| Engine sensor failure | electrical | 1 | 0 | — | — | — | 0.0 | $180–$900 | Moderate |
| Infotainment screen failure | infotainment | 1 | 0 | — | — | — | 0.0 | $400–$2,600 | Low |
| Backup camera failure | infotainment | 1 | 0 | — | — | — | 0.0 | $250–$1,200 | Moderate |
| Brake line, hose or caliper failure | brakes | 1 | 0 | — | — | — | 0.0 | $250–$1,600 | Critical |
| Loss of power steering | steering | 1 | 0 | — | — | — | 0.0 | $600–$2,800 | Critical |
| Tire blowout or tread separation | wheels | 1 | 1 | — | 7k | — | 0.0 | $200–$1,500 | Critical |
| Rust or structural corrosion | body | 1 | 0 | — | — | — | 0.0 | $500–$6,000 | High |
| Blower motor or climate control failure | hvac | 1 | 0 | — | — | — | 0.0 | $250–$1,200 | Moderate |
| Wiper or washer failure | glass | 1 | 1 | — | 37k | — | 0.0 | $120–$800 | Moderate |
| Other suspension problem | suspension | 1 | 0 | — | — | — | 0.0 | $350–$2,000 | Moderate |
| Other seat belt problem | airbag | 1 | 1 | — | 123k | — | 0.0 | $200–$900 | High |
| Unclassified problem | other | 39 | 10 | 9k | 15k | 47k | 1.1 | — | Moderate |
Rate per 1,000 uses a fleet-size estimate derived from recall paperwork for this exact model year. It is a lower bound. Repair costs are typical independent-shop ranges for the failure, not figures from these reports.
How often, against how many were built
Scaled by an estimate of how many of these cars exist, the 2018 Hyundai Sonata draws about 16 per 1,000 vehicles, which puts it in the 93rd percentile of complaint rates among 2018 vehicles we can rate.
That denominator is the weakest number on the page and it is fair to say so plainly. Rate per 1,000 uses a fleet-size estimate derived from recall paperwork for this exact model year. It is a lower bound.
The working figure is 34,815 vehicles. If the true number is twice that, every rate on this page is half what it says; the ranking against other 2018 vehicles, which is what the risk score uses, is far more robust than the rate itself.
What owners wrote
Verbatim from NHTSA complaint narratives, trimmed for length. The odometer reading is the one the owner gave.
Other engine problem
Purchased new 2018 sonata sel model in california. While driving, the transmission starts to hard downshift when the brake is applied. I found out that this hard downshifting and jolting/thumping of engine and transmission only occurs when coming to a stop at speeds between 10 to 15mph. It can be described as follows, after the brake pedal has been gently applied and lightly released but then the car itself applied its brake again. It terrifies the driver's driving conditions, mentally and physically.
Recalls on the 2018 model year
NHTSA has issued 1 recall campaign covering the 2018 Hyundai Sonata, affecting an estimated 34,815 vehicles. A recall is a different kind of evidence from a complaint: it is the regulator and the manufacturer agreeing that something has to be fixed, and the fix is free for as long as the car exists.
The campaigns cover latches/locks/linkages:trunk lid:latch. Whether the work was actually done on the car in front of you is a question only the VIN can answer, and the manufacturer or NHTSA will answer it free.
One caution about reading these together: a recall usually raises the complaint count for the same part, because owners who read about it go and file. The mileages stay informative; the counts get noisy.
LATCHES/LOCKS/LINKAGES:TRUNK LID:LATCH
348,158 vehicles 2021-08-06- Defect
- Hyundai Motor America (Hyundai) is recalling certain 2017-2018 Sonata, 2016-2018 Sonata Hybrid, 2018-2020 Accent, and 2016-2017 Azera vehicles. The trunk latch may become damaged, preventing the opening of the trunk from the inside. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 401, "Internal Trunk Release."
- Consequence
- A person inside the trunk compartment may become trapped, increasing their risk of injury.
- Remedy
- Dealers will replace the trunk latch base, free of charge. Owner notification letters were mailed December 4, 2021. Owners may contact Hyundai customer service at 1-855-371-9460. Hyundai's number for this recall is 208.
Recall work is free at a franchised dealer regardless of the car's age. Check the VIN at nhtsa.gov/recalls before assuming it was done.
How it ranks in the 2018 field
The score at the top of the page, placed among its peers. The zones are the same thresholds the scorer applies, read out of the scorer itself, so the picture and the band word cannot disagree.
Scores are ranked within the model year, never across years, because an older car has had longer to accumulate reports.
- Left fewer and less serious reports
- Right more, or worse
- Marker this vehicle
Better and worse years of the same car
Severe risk for a 2018 — 65th riskiest of the 251 2018 vehicles we can rate. Because the ranking is against the same model year only, age cancels out of it.
Across the 30 model years of this car that carry enough reports to score, 1996 comes out best at 58 and 2022 worst at 81, with 2018 itself at 79.
If the model year is negotiable, 1996, 1998, 2000, 1997, 1999, 2008, 2007, 2001, 2004, 2025, 2024, 2006, 2010, 2002, 2003, 2009, 2023, 2014, 2005, 2019, 2012, 2017 and 2013 score lower than 2018 by a margin worth acting on. Same body, same engines, different luck — usually a supplier change or a mid-cycle fix, which the complaint data can show but never explain.
Within the 2011–2019 generation specifically, 2014 is the strongest year at 72 and 2015 the weakest at 79.
Scores compare each year against other cars of the same model year, so a low number on an older car is a real result and not an artefact of age.
Shorter is better. Years with too few reports to score are shown without a bar rather than as a zero, because no data is not good news.
Within the 2011-2019 generation, 2014 Hyundai Sonata scores best at 72 and 2015 Hyundai Sonata worst at 79.
Where to spend the inspection money
The mileages below are where the first quarter of reports for each mode had already been filed, which makes them the point at which a fault is worth looking for rather than the point at which it happens: headlight failure or clouding from about 91, other speed control problem from about 5k, wiring harness or short circuit from about 5k and cruise control failure from about 7k.
On a 2018 Hyundai Sonata with more miles than that on it, the useful question to put to a seller or a mechanic is whether headlight failure or clouding has been dealt with, and if so with what parts and at whose expense. A car that has already had the repair is in a different position from one that has not.
Treat it as where to point the inspection, not as a prediction. A well-maintained example can sail past every mileage on this page, and a neglected one can fail well before the first of them.
Where these figures stop being useful
550 owner reports; fleet size estimated from this year's own recall paperwork. Every count on this page is therefore a floor: it is the number of owners who went to the trouble of filing with a federal agency, which is a small and self-selected fraction of the owners who had the fault.
Of those 550 reports, 202 carried an odometer reading, so the mileages here describe 37% of the sample rather than all of it. Owners also round: readings pile up on multiples of ten thousand, which is why this site publishes "about 90,000 miles" and not "91,438".
The failure modes are assigned by software reading the owner's own words, which is accurate in bulk and wrong in individual cases. A mode with a handful of reports may contain a misfiled one.
And nothing here predicts what one car will do. These are other people's complaints, filed years apart, on cars maintained by strangers. Read the page as a map of where this model year has previously gone wrong, then have the specific car in front of you inspected.
Questions this page answers
What are the most common problems with the 2018 Hyundai Sonata?
The most-reported failures are other engine problem (85 reports, median 42,500 miles), excessive oil consumption (54 reports, median 80,000 miles) and other electrical problem (31 reports, median 35,000 miles). Counts come from owner complaints filed with NHTSA, which are voluntary, so they show what owners bothered to report rather than every fault that occurred.
At what mileage do 2018 Hyundai Sonata problems start?
Headlight failure or clouding is the earliest failure mode to show up, with a median reported mileage of 1,900 miles and a quarter of reports before 100 miles. Across all failure modes on this year, the median report sits at 20,000 miles.
Is the 2018 Hyundai Sonata reliable?
It scores 79 out of 100 on our risk index, which is severe — 65th riskiest of the 251 2018 vehicles we can rate. The score is a comparison against other 2018 vehicles, not a prediction about any individual car, and it is built from complaint rates, severity and how early failures appear.
Which year of the Hyundai Sonata is best?
Within the 2011–2019 generation, 2014 scores best at 72 out of 100 and 2015 worst at 79. Same body, same engines, different luck.
Where this comes from. Every figure above is computed from NHTSA owner complaints and recall records for this exact make, model and year. Complaints are voluntary and self-selected, so treat counts as a floor. The methodology page writes out each formula, and the same numbers are available as JSON.
What breaks at my mileage Compare with another car
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed