Most common 2018 Kia Optima problems
Share of the 232 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Kia Optima complaints by model year
Best Optima years: 2010, 2009, 2008. Years to avoid: 2013, 2015, 2012, 2016, 2011. Compare all years →
2018 Kia Optima recalls (2)
Latches/locks/linkages › Trunk lid › Latch
Kia America, Inc. (Kia) is recalling certain 2016-2017 Rio, 2016-2018 Optima, 2017-2018 Optima Hybrid and Optima Plug-in Hybrid vehicles. The trunk latch base may crack, preventing the opening of the trunk from the inside.
Remedy: Dealers will replace the trunk latch base subassembly, free of charge. Owner notification letters were mailed October 19, 2023. Owners may contact Kia customer service at 1-800-333-4542.
Hybrid propulsion system
Kia Motors America (Kia) is recalling certain 2017-2018 Kia Optima hybrid vehicles. These vehicles are equipped with a Voltage Protection Device (VPD), designed to protect the high voltage battery module, that may activate inadvertently.
Remedy: Kia will notify owners, and dealers will remove the VPD switch and install two newly designed Battery Management Systems (BMS) that contain Overvoltage Protection Devices (OPDs), free of charge.
NHTSA defect investigations
Federal safety investigators have looked into 2 possible defects involving the 2018 Kia Optima:
Electrical overstress
The Office of Defects Investigation (ODI) opened this investigation to determine if the failure of airbags to deploy during severe crashes, in certain vehicles, was the result of a safety related defect. During the investigation a complex failure was studied that can result in non-deployment of subject vehicle air bags and other restraint system devices in severe crash events.
Loss of Motive Power
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021.
What 2018 Kia Optima owners say
Engine & cooling all 143 →
The contact owns a 2018 Kia Optima. The contact stated that while his wife was driving at an undisclosed speed, the vehicle went into LIMP Mode, and the check engine warning light was illuminated. The vehicle was restarted; however, the failure recurred while driving. The vehicle was taken to the dealer, where it was diagnosed and determined that the spark plugs had failed and needed to be replaced. The vehicle was repaired; however, the failure recurred while driving. The vehicle was towed to the dealer, where it was diagnosed that the engine had failed and needed to be replaced. The contact was informed by the dealer that the repair could not be covered due to the poor maintenance of the vehicle; however, upon providing all the maintenance records, the dealer informed the contact that the vehicle could not be repaired unless the engine had fully seized. …
The contact owns a 2018 Kia Optima. The contact stated while driving approximately 40 MPH, the accelerator pedal was depressed; however, the vehicle failed to respond as needed. The contact stated that there was an abnormal growling sound coming from under the floorboard, and the engine was making an abnormal knocking sound. The contact stated that the RPM gauge was revving high while depressing the accelerator pedal; however, the vehicle failed to respond. The contact pulled over and turned off and restarted the vehicle; however, the vehicle was not running normally. The contact stated that the failure was a recurring failure. Additionally, the contact stated that vehicle was consuming approximately one quart of engine oil per week and the transmission was hesitating and was making the vehicle jerk while shifting gear. …
Electrical system all 33 →
The contact owns a 2018 Kia Optima. The contact stated that the vehicle was sputtering while being started. The contact stated that the vehicle also sputtered while driving at various speeds, and while reversing. The check engine warning light was illuminated. The vehicle was taken to the dealer and the contact was informed that oil was getting onto the spark plugs and ignition coils. The spark plugs and ignition coils were replaced; however, the failure persisted. The manufacturer was not made aware of the failure. The approximate failure mileage was 70,000.
Was driving on the interstate. The only light on was the ABS light and the car started smoking. Had to come to a stop as they were sparks coming from out under the car through it into park at around 15 mph steel jumped out of the car and within a minute the car was fully engulfed in flames.
Transmission & drivetrain
The contact owns a 2018 Kia Optima. The contact stated while driving approximately 40 MPH, the accelerator pedal was depressed; however, the vehicle failed to respond as needed. The contact stated that there was an abnormal growling sound coming from under the floorboard, and the engine was making an abnormal knocking sound. The contact stated that the RPM gauge was revving high while depressing the accelerator pedal; however, the vehicle failed to respond. The contact pulled over and turned off and restarted the vehicle; however, the vehicle was not running normally. The contact stated that the failure was a recurring failure. Additionally, the contact stated that vehicle was consuming approximately one quart of engine oil per week and the transmission was hesitating and was making the vehicle jerk while shifting gear. …
The contact owns a 2018 Kia Optima. The contact stated that while driving at an undisclosed speed, the vehicle was jerking. The vehicle was taken to the dealer; however, no cause for the failure was found. The vehicle was then taken to Battleground Kia of Greensboro (2927 Battleground Ave, Greensboro, NC 27408) but no cause for the failure was found. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 60,000.
2018 Kia Optima engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 2.0L 4-cyl hybrid | 6-speed dual-clutch | FWD | 39 / 46 / 42 |
| 2.0L 4-cyl plug-in hybrid | 6-speed dual-clutch | FWD | 38 / 43 / 40 |
| 1.6L 4-cyl turbo | 7-speed dual-clutch | FWD | 28 / 37 / 31 |
| 2.4L 4-cyl | 6-speed automatic | FWD | 25 / 36 / 29 |
| 2.0L 4-cyl turbo | 6-speed automatic | FWD | 22 / 31 / 25 |
EPA ratings. Class: Midsize car.
Frequently asked questions
Is the 2018 Kia Optima a good car?
Based on 232 owner complaints filed with NHTSA, the 2018 Optima rates use caution: 1.9× as many complaints as a typical year of the Optima at the same age. It is one of the Optima years we suggest avoiding. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2018 Kia Optima?
The engine & cooling — 143 complaints, 62% of all complaints for this model year, most often about engine › oil/lubrication. Next are the electrical system (33) and transmission & drivetrain (18).
How many recalls does the 2018 Kia Optima have?
There are 2 recalls for the 2018 Kia Optima, the most recent from August 24, 2023 (latch). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Kia Optima?
The best years by complaints, compared at the same age, are 2010, 2009 and 2008. Years to avoid or approach with caution: 2013, 2015, 2012, 2016 and 2011. See the full Kia Optima years comparison.
At what mileage do 2018 Kia Optima problems happen?
The median mileage reported in complaints is about 45,000 miles; 52% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.