Showing the 2021 K5 GT-Line. We haven't verified this trim's engine; the numbers below cover every version of this model year. Every version
Owner complaints, recalls, fuel economy and safety ratings from public NHTSA and EPA data, updated Oct 18, 2026.
Fuel economy
27–32 mpgcombined; city 24–29, highway 32–38; every version of this model year
Five years of fuel
$10,150–$12,030U.S. average; Ohio $9,070–$10,750 at local prices; every version of this model year; fuel only, not other costs of owning it; 15,000 miles a year, at EIA fuel prices for the week of Oct 12, 2026
NHTSA's VIN data lists these trims for the 2021 K5. A trim's engine and numbers are shown as its own only where EPA names versions after the trim and no other version could be it; "seen with" means a source shows that engine on the trim, not that it was the only one. Recalls and complaints cover the whole model year: whether a recall applies to a car depends on its VIN, on NHTSA's recall lookup.
Owners have filed 169 complaints with NHTSA about the 2021 K5. These are unverified owner reports, counted by the part of the car they name; one complaint can name several parts. Counts aren't adjusted for how many were sold, so they don't show how reliable a car is.
Complaints by part of the car
Part
Complaints
Crashes
Fires
Injuries
Electrical system
46
0
2
0
Fuel/propulsion system
44
0
0
0
Unknown or other
32
2
0
1
Engine
30
0
1
0
Power train
19
0
0
0
Fuel system, gasoline
13
0
0
1
Air bags
10
5
0
5
Service brakes
10
0
0
0
Structure
10
0
0
0
Forward collision avoidance
9
0
0
0
Lane departure
9
1
0
0
Seats
8
1
0
2
7 more parts
Steering
7
0
0
0
Visibility/wiper
5
0
0
0
Back over prevention
3
0
0
0
Engine and engine cooling
3
0
0
0
Exterior lighting
3
0
0
0
Vehicle speed control
2
0
0
0
Tires
1
0
0
0
What the columns count
Complaints: complaints that name that part. One complaint can name several parts, so the rows overlap and don't add up to the total.
Crashes and Fires: complaints that report one. Two owners can file about the same event, and NHTSA doesn't link them, so these count reports, not events.
Injuries: the number of people the complaints say were injured.
None of these columns shows that a part caused a crash, fire or injury: they're what owners reported, unverified.
Complaints by model year
Newer years have had less time to collect complaints, and counts aren't adjusted for sales, so a shorter bar doesn't mean a more reliable year.
NHTSA lists 6 recall campaigns for the 2021 K5 over its history. Campaigns are matched by model and year, so each one may apply to a given car, and its repair may already be done: check a VIN on NHTSA's recall lookup for the open recalls on that exact car.
Fuel system, gasoline
NHTSA campaign 25V794000 · reported Nov 17, 2025 · 250,547 vehicles potentially affected across the whole campaign
Remedy: Dealers will replace the check valve. The fuel tank will be inspected for damage and replaced as necessary. All repairs will be performed free of charge. Owner notification letters were mailed January 16, 2026. Owners may contact Kia customer service at 800-333-4542. Kia's number for this recall is SC356. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning December 1, 2025.
Kia America, Inc. (Kia) is recalling certain 2021-2024 K5 vehicles. A damaged check valve can allow air to enter the fuel tank, causing it to expand and contact hot exhaust components, melting the tank.
Risk: A melted fuel tank can leak, increasing the risk of a fire.
NHTSA campaign 23V149000 · reported Mar 7, 2023 · 188,912 vehicles potentially affected across the whole campaign
Remedy: Dealers will inspect and reinstall the side curtain air bags, as necessary, free of charge. Owner notification letters were mailed April 7, 2023. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC263.
Kia America, Inc. (Kia) is recalling certain 2021-2023 K5 vehicles. The side curtain air bags may have been installed incorrectly, causing them not to deploy properly in the event of a crash.
Risk: Air bags that do not deploy as intended can increase the risk of injury in a crash.
NHTSA campaign 22V760000 · reported Oct 11, 2022 · 69,038 vehicles potentially affected across the whole campaign
Remedy: Dealers will inspect and replace the transmission, as necessary. Dealers will also update the transmission control unit software. All repairs will be performed free of charge. Owner notification letters were mailed December 9, 2022. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC250.
Kia Motors, Inc. (Kia) is recalling certain 2021-2022 Sorento and 2021-2023 K5 vehicles. The vehicle's "fail-safe" limited-mobility drive mode may be impaired, when prompted by a transmission oil pump malfunction, which can result in a complete loss of drive power.
Risk: Loss of drive power increases the risk of a crash.
NHTSA campaign 21V519000 · reported Jul 8, 2021 · 21,575 vehicles potentially affected across the whole campaign
Remedy: Dealers will inspect and tighten, or replace the fuel pipe as necessary, free of charge. Owner notification letters were mailed July 21, 2021. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC214.
Kia Motor America (Kia) is recalling certain 2021 Sorento and 2021-2022 K5 vehicles equipped with 2.5L turbocharged engines. Fuel may leak at the pipe connection between the high-pressure fuel pump and fuel rail.
NHTSA campaign 21V447000 · reported Jun 14, 2021 · 846 vehicles potentially affected across the whole campaign
Remedy: Dealers will update the R-MDPS software, free of charge. Owner notification letters are were mailed June 24, 2021. Owner may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC213.
Kia Motors America (Kia) is recalling certain 2021-2022 K5 vehicles equipped with 2.5L T-GDI engines. The Rack-Mounted Motor Driven Power Steering (R-MDPS) system lacks the ability to diagnose communication faults. If a communication fault occurs while driving around a curve with Lane Following Assist (LFA) engaged, the steering assist level may not adjust properly, causing a sudden increase in the steering effort required.
Risk: A sudden increase in steering effort can increase the risk of a crash.
Air bags: air bag/restraint control module; Air bags: sensor
NHTSA campaign 21V164000 · reported Mar 11, 2021 · 142 vehicles potentially affected across the whole campaign
Remedy: Kia will notify owners, and dealers will replace the OCS/ODS unit, free of charge. The recall began March 18, 2021. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC207.
Kia Motors America (Kia) is recalling certain 2021 Telluride, K5, and Forte vehicles. The Occupant Classification and Detection System (OCS/ODS) unit may not detect the presence of a child restraint system in the front passenger seat. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 208, "Occupant Crash Protection."
Risk: In the event of a crash, deployment of the front passenger air bag, with a child in that seat, can increase the risk of injury to the child.
Carmakers sent NHTSA 134 service bulletins and notices that cover the 2021 K5, the latest on Jun 18, 2026. They tell dealers how to fix known issues.
The parts they mention most: electrical system (81), equipment (20), engine and engine cooling (18), power train (18), fuel/propulsion system (13).
NHTSA hasn't opened a defect investigation that covers this model year.
Maintenance
Oil
The owner's manual gives the oil and how often to change it. We show oil facts only once we've checked them against the manual, and we haven't yet for the 2021 K5.
EPA class: large cars. EPA greenhouse gas score: 6–7 out of 10. Each version EPA tested:
Swipe the table sideways for more columns.
Version
Engine
Transmission
Fuel
City / hwy / comb
K5 Front-Wheel Drive
1.6 L, 4 cyl, turbo
Automatic (S8)
Regular Gasoline
29 / 38 / 32
K5 Front-Wheel Drive
1.6 L, 4 cyl, turbo
Automatic (S8)
Regular Gasoline
27 / 37 / 31
K5 All-Wheel Drive
1.6 L, 4 cyl, turbo
Automatic (S8)
Regular Gasoline
26 / 34 / 29
K5 Front-Wheel Drive
2.5 L, 4 cyl, turbo
Automatic (AM-S8)
Regular Gasoline
24 / 32 / 27
Sources and dates
U.S. EPA fuel economy data, file of Sep 29, 2026
NHTSA owner complaints, file of Oct 17, 2026
NHTSA recalls, file of Oct 17, 2026
NHTSA manufacturer communications, file of Oct 17, 2026
NHTSA defect investigations, file of Oct 17, 2026
NHTSA 5-Star Safety Ratings, file of Aug 7, 2026
U.S. Energy Information Administration, file of Oct 12, 2026
Fuel cost: EPA mpg with fuel prices for the week of Oct 12, 2026 and electricity prices for Jul 2026. Source: U.S. Energy Information Administration (Oct 2026). Complaints are unverified reports owners filed with NHTSA. About the data