How many NHTSA complaints have been filed about the 2018 Kia Optima?

224 NHTSA complaints have been filed about the 2018 Kia Optima between 2018-01-20 and 2026-06-10. Top reported components: ENGINE (127), UNKNOWN OR OTHER (37), ELECTRICAL SYSTEM (33). Source: NHTSA Office of Defects Investigation.

2018 Kia Optima Maintenance Schedule

Manufacturer-recommended service intervals for the Service Reminder and open recall alerts for your 2018 Kia Optima.

Make this page yours

Personalize for your car and your area

ZIP unlocks trusted shops near you. Mileage unlocks personalized service due dates. Either or both — your call.

Your ZIP stays with us. We share your city with shops, never your ZIP. Read our Promise →

How Kia schedules service: Service Reminder

Kia uses Hyundai Motor Group's powertrains, so service intervals mirror Hyundai's. Kia Promise covers the first 3 years / 36,000 miles of complimentary maintenance. Kia owners with the Theta II 2.0L/2.4L (Optima, Sorento, Sportage 2011-2019) should adhere strictly to oil intervals due to known oil-consumption issues in Kia TSBs.

2 Open Recalls

Source: NHTSA

HYBRID PROPULSION SYSTEM

Campaign #18V161000 · 08/03/2018

Issue: 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.

Risk: If the VPD activates while the vehicle is being operated in Electric Vehicle (EV) mode, there may be a loss of power, increasing the risk of a crash.

Fix: 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. The recall is expected to begin May 2018. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC162.

LATCHES/LOCKS/LINKAGES:TRUNK LID:LATCH

Campaign #23V594000 · 24/08/2023

Issue: 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. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 401, "Internal Trunk Release."

Risk: A person inside the trunk compartment may become trapped, increasing their risk of injury.

Fix: 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. Kia's number for this recall is SC278.

Recall data refreshed Jun 7, 2026.

Essential maintenance

Critical for safety and preventing major damage

🛢️

Engine Oil & Filter

Every 3,750 mi

Severe service: every 3,750 miles. Normal: 7,500 miles. Theta II 2.0L/2.4L on Optima, Sorento, Sportage (2011-2019): full synthetic only, never extend.

Estimated cost — typical U.S. ranges

Dealer

~$120–$160

Shop

~$85–$115

DIY

~$25–$55

Full synthetic costs more than conventional. 5-quart 0W-20 + filter is the typical bill.

🔄

Tire Rotation

Every 7,500 mi

Rotate tires every 7,500 miles. Telluride and Sorento AWD owners benefit from rotation every 5,000 miles to prevent uneven wear.

Estimated cost — typical U.S. ranges

Dealer

~$85

Shop

~$60

DIY

Free

Often free at the shop where you bought the tires — worth asking before paying.

🛑

Brake Inspection

Every 7,500 mi

Inspect brake pads and rotors every 7,500 miles. Forte and Soul front pads typically last 40,000-55,000 miles.

Estimated cost — typical U.S. ranges

Dealer

~$85

Shop

~$60

DIY

Free

Most shops do this free as a courtesy with any service. Don't pay separately if you can avoid it.

🧪

Brake Fluid

Every 30,000 mi

Replace DOT 3 brake fluid every 30,000 miles or 24 months. Required for ABS and ESC pump longevity.

Every 60,000 mi

Sportage AWD, Sorento AWD, Telluride AWD: replace transfer case fluid and rear diff fluid every 60,000 miles.

Estimated cost — typical U.S. ranges

Dealer

~$105–$140

Shop

~$75–$100

DIY

~$15–$40

AWD/4WD vehicles only. Easy drain-and-fill on most platforms.

Recommended maintenance

Extends the life of your vehicle and improves comfort

🌬️

Cabin Air Filter

Every 15,000 mi

Replace cabin air filter every 15,000 miles. Located behind the glove box on Optima, Forte, and Sportage; behind the dashboard panel on Telluride.

Estimated cost — typical U.S. ranges

Dealer

~$60–$95

Shop

~$45–$70

DIY

~$15–$40

Usually behind the glovebox. Shops charge labor for a 10-minute job — easy DIY win.

Known issues for this vehicle

What drivers and federal regulators have officially reported about the 2018 Kia Optima.

Reported to NHTSA

NHTSA has 224 complaints on file for the 2018 Kia Optima (2018-01 → 2026-06). We haven't reviewed and grouped them yet for this specific YMM — for now, the full list lives on NHTSA.

Top reported components: ENGINE (127) · UNKNOWN OR OTHER (37) · ELECTRICAL SYSTEM (33)

Read all complaints on NHTSA →

Note: NHTSA also opened 2 defect investigations on this vehicle that closed without action.

Issues on other model years

Source: NHTSA Office of Defects Investigation (ODI). Complaint data refreshed Jun 13, 2026. Investigation data refreshed Jun 13, 2026.

We display NHTSA's record with attribution; we don't editorialize on what these complaints mean for any specific vehicle.

Typical U.S. ranges. Actual quotes vary by shop, parts choice, and vehicle condition.

How we estimate: Dealer = OEM parts × 1.4 + labor × $165/hr. Shop = parts + labor × $115/hr. DIY = parts only.

This maintenance schedule for the 2018 Kia Optima reflects Kia's published service intervals and the Service Reminder system. Your actual service needs may vary based on driving conditions, climate, and vehicle usage. Always consult your owner's manual for model-specific recommendations.

Check another vehicle →