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2018 Kia Optima Hybrid

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2018 Optima Hybrid.

Body PASSENGER CARTransmission Automatic (AM6)

The 2018 Kia Optima Hybrid is a passenger car fitted with an automatic (AM6) transmission, carrying EPA fuel-economy ratings of 39/46/42 mpg city/highway/combined and an engine-oil capacity of 4.7 quarts with recommended viscosities of 5W-20, 5W-30, or 10W-30. Within the 2011–2020 Optima Hybrid complaint record, the 2018 model year accounts for only three owner complaints and two recalls, with engine issues representing the top complaint category. That volume sits far below the 2019 high of 201 complaints and just above the 2020 low of one, marking 2018 as one of the more lightly reported years in this generation's reliability history.

Model year20182017201620152014201320122011

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity4.7 qtOEM · verified
Engine oil type5W-20 / 5W-30 / 10W-30OEM · verified
Lug nut torque79-94 ft-lbsOEM · verified
EPA fuel economy39/46/42 mpgEPA · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 48 · 760 CCA battery. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 48 · 760 CCAOEM · verified
Tail / brake / turnHEADLAMPOEM · verified
Tire sizeP215/55R17OEM · verified
Wheel / rim7.0 inOEM · verified

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic (AM6)

Dimensions & weight NHTSA vPIC

Overall length191.3 in
Overall width73.2 in
Overall height57.5 in
Wheelbase110.6 in
Curb weight3490 lb
Track (front / rear)62.2 / 63 in
Weight distribution (front / rear)61/39

Ratings & economy EPA / vPIC

EPA city / highway / combined39 / 46 / 42 mpg
DrivetrainFront-Wheel Drive
Passenger volume105 cu ft
Cargo volume13 cu ft
Recommended fuelRegular Gasoline

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 4.7 qt of 5W-20 / 5W-30 / 10W-30 engine oil, DOT 3 brake fluid. Torque lug nuts to 79-94 ft-lbs. The firing order is 1-3-4-2. Note the cylinder-head bolts finish on a torque angle (torque-to-yield) — they stretch permanently and should be replaced, not reused, during any head service.

Lubricants & capacities

Automatic Transmission FluidATF
Automatic Transmission Fluid Capacity6.3
Brake FluidDOT 3
Engine CoolantEthylene Glycol
Engine Coolant Capacity7.9
Engine Oil5W-20 · 5W-30 · 10W-30
Engine Oil Capacity4.7 qt
Power Steering FluidEPS

Engine torques

Crankshaft Position (CKP) Sensor Bolt(s)5.8-8.7 ft-lbs
Camshaft Position (CMP) Sensor Bolt(s)5.8-8.7 ft-lbs
Crankshaft Position (CKP) Sensor Bolt(s)7.2-8.7 ft-lbs
Camshaft Position (CMP) Sensor Bolt(s)7.2-8.7 ft-lbs
Crankshaft Position (CKP) Sensor Bolt(s)7.2-8.7 ft-lbs
Camshaft Position (CMP) Sensor Bolt(s)7.2-8.7 ft-lbs
Camshaft Sprocket and/or Gear Bolt(s)47.0-54.2 ft-lbs
Cylinder Head InstructionsUse new bolts only, do not reuse old bolts.

Chassis torques

Lug Nuts79-94 ft-lbs
Lug Nuts79-94 ft-lbs
Lug Nuts79-94 ft-lbs
Lug Nuts79-94 ft-lbs

Ignition

Cylinder Firing Order1-3-4-2
Curb Idle Speed (No Load)640 rpm
Curb Idle Speed Variance (No Load)100 rpm
Curb Idle Speed (Secondary Under Load)660 rpm
Curb Idle Speed Variance (Secondary Under Load)100 rpm
Curb Idle Speed (No Load)640 rpm
Curb Idle Speed Variance (No Load)100 rpm
Curb Idle Speed (Secondary Under Load)660 rpm

Battery & A/C

RefrigerantR134a
Refrigerant Capacity1.38-1.54 lbs
Oil GroupPAG
Oil Type46
Oil Capacity3.05-3.71 oz
RefrigerantR1234yf
Refrigerant Capacity1.16-1.26 lbs.
Oil GroupPOE

Service checks

Regulated Fuel System Pressure (With Vacuum)70.0-75.0 psi
Fuel Pump Pressure Minimum42.0 psi
Regulated Fuel System Pressure (With Vacuum)42.0 psi
Fuel Pump Pressure Minimum42.0 psi
Regulated Fuel System Pressure (With Vacuum)42.0 psi
Fuel Pump Pressure Minimum70.0 psi
Fuel Pump Pressure Maximum75.0 psi
Regulated Fuel System Pressure (With Vacuum)70.0-75.0 psi

Brakes

Brake Caliper Bolt to Carrier Torque16-23
Brake Caliper Carrier to Hub Bolt Torque58-72
Brake Caliper Bolt to Carrier Torque16-23
Brake Caliper Carrier to Hub Bolt Torque58-72
Brake Caliper Bolt to Carrier Torque16-23
Brake Caliper Carrier to Hub Bolt Torque58-72
Brake Caliper Bolt to Carrier Torque16-23
Brake Caliper Carrier to Hub Bolt Torque58-72

Multi-step torque procedures OEM · verified

Camshaft Bearing/Carrier Cap Bolts or Studs — tightening sequence 4 stages
1M6 Bolts52 in
2M6 Bolts104–112 in
3M8 Bolts84 in
414.0-17.0
Camshaft Bearing/Carrier Cap Bolts or Studs — tightening sequence 2 stages

Prep M6 Bolts

152.0 inch lbs.52 in
296.0-112.0 inch lbs.; M8 Bolts96–112 in
123.0-26.0 ft. lbs.23–26 ft. lbs
Camshaft Bearing/Carrier Cap Bolts or Studs — tightening sequence 1 stages

Prep M6 Bolts

196.0-112.0 inch lbs.; M8 Bolts96–112 in
120.0-23.0 ft. lbs.20–23 ft. lbs
Connecting Rod (Large End) Bearings — tightening sequence 2 stages
113.0-16.0 ft. lbs.13–16 ft. lbs
290.0
Connecting Rod (Large End) Bearings — tightening sequence 2 stages
113.0-16.0 ft. lbs.13–16 ft. lbs
285.0
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
148.0-53.0 ft. lbs., Step 2: 39-4148–53 ft. lbs
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
134.0-38.0 ft. lbs., Step 2: 78-8234–38 ft. lbs
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
134.0-38.0 ft. lbs., Step 2: 78-8234–38 ft. lbs
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
134.0-38.0 ft. lbs., Step 2: 78-8234–38 ft. lbs
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
134.0-38.0 ft. lbs., Step 2: 78-8234–38 ft. lbs
Cylinder Head — tightening sequence 3 stages

Prep Do not reuse old bolts. Do not lubricate cylinder head bolts with engine oil. Apply Loctite 5900H or equivalent on the front edge of the cylinder head gasket on both sides. Cylinder head must be assembled within 5 minutes of applying sealant.

124.0-27.0 ft. lbs.24–27 ft. lbs
290 degrees-95 degrees90 degrees
390 degrees-95 degrees90 degrees
Cylinder Head — tightening sequence 3 stages

Prep Do not reuse old bolts. Do not lubricate cylinder head bolts with engine oil. Apply Loctite 5900H or equivalent on the front edge of the cylinder head gasket on both sides. Cylinder head must be assembled within 5 minutes of applying sealant.

124.0-27.0 ft. lbs.24–27 ft. lbs
290 degrees-95 degrees90 degrees
390 degrees-95 degrees90 degrees
Cylinder Head — tightening sequence 3 stages

Prep Do not reuse old bolts. Do not lubricate cylinder head bolts with engine oil. Apply Loctite 5900H or equivalent on the front edge of the cylinder head gasket on both sides. Cylinder head must be assembled within 5 minutes of applying sealant.

124.0-27.0 ft. lbs.24–27 ft. lbs
290 degrees-95 degrees90 degrees
390 degrees-95 degrees90 degrees
Cylinder Head — tightening sequence 3 stages

Prep Do not reuse old bolts. Do not lubricate cylinder head bolts with engine oil. apply liquid gasket threebond 1217H or equivalent on the edge of the cylinder block and head gasket. Cylinder head must be assembled within 5 minutes of applying sealant.

124.0.0-27.0 ft. lbs.
290 degrees-95 degrees90 degrees
390 degrees-95 degrees90 degrees
Cylinder Head — tightening sequence 3 stages
124-27 ft. lbs.24–27 ft. lbs
2Turn 90-95 degrees90–95 degrees
390-95
Intake Manifold to Engine Bolts — tightening sequence 1 stages
113.7-17.4
Main Bearings — tightening sequence 2 stages
113.0-16.0 ft. lbs.13–16 ft. lbs
290.0
Main Bearings — tightening sequence 3 stages
111.0. ft. lbs.
220.0-23.0 ft. lbs.20–23 ft. lbs
3120.0-125.0
Main Bearings — tightening sequence 3 stages
111.0 ft. lbs.11 ft. lbs
220.0-23.0 ft. lbs.20–23 ft. lbs
3120.0-125.0
Engine Valve Cover Bolts — tightening sequence 1 stages
12.9-4.3 ft. lbs., Step 2: 5.8-7.22.9–4.3 ft. lbs
Engine Valve Cover Bolts — tightening sequence 1 stages
12.9-4.3 ft. lbs., Step 2: 5.8-7.22.9–4.3 ft. lbs
Engine Valve Cover Bolts — tightening sequence 1 stages
12.9-4.3 ft. lbs., Step 2: 5.8-7.22.9–4.3 ft. lbs

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 6,500 mi; spark plugs every 45,000 mi; coolant every 30,000 mi. The big-interval services (every 30,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

Every 6,500 miEngine Oil (drain & refill) · Engine Oil Filter (replace)
Every 7,500 miAccessory Drive Belt (inspect) · Air Intake Duct (inspect) · Engine Air Filter Element (inspect) · Fuel Tank (add fluid conditioner) · Intercooler (inspect) · Tire & Wheel Assembly (rotate)
Every 15,000 miAccessory Drive Belt (inspect) · Air Conditioning System (inspect) · Brake Line (inspect) · Brake Linings (inspect) · Brake Rotor (inspect) · CV Joint Boot (inspect)
Every 30,000 miBrake Hydraulic System (inspect fluid level) · Engine Coolant System (drain, flush & refill) · Fuel Evaporative Canister Filter (inspect) · Fuel Evaporative Emission Control System Lines (inspect) · Fuel Line (inspect) · Fuel Tank Filler Cap (inspect)
Every 37,500 miTransmission Assembly (inspect fluid level)
Every 45,000 miSpark Plugs (replace)
At 60,000 miAccessory Drive Belt (inspect)
Every 60,000 miDrive Belt (replace) · Engine Valves (inspect valve lash)
At 120,000 miEngine Coolant System (drain, flush & refill) · Hybrid Inverter (drain, flush & refill coolant)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

The 2018 Optima Hybrid shows a marked decline in complaints, falling from 25 in 2017 to just 3, while recalls held steady at two and investigations remained at three, with technical service bulletins dropping to 47. Across the generation, complaints peaked at 107 in 2012, fell to a low of 4 in 2016, rose slightly in 2017, reached another low in 2018, then surged to 201 in 2019 before dropping again to 1 in 2020. Recalls mirrored this trend, with zero recalls from 2014‑2016, two recalls in both 2017 and 2018, and a single recall in 2019. The top complaint areas for 2018 each involved a single report related to the engine, power‑train, or electrical/fuel/propulsion systems, and there were no crash or fire complaints recorded. Given the notably low complaint and recall counts in 2018 relative to the surrounding years, this model year presents a favorable option for a used purchase, though the sharp increase in complaints the following year suggests reviewing the vehicle’s service history is prudent.

2
Open recalls
NHTSA campaigns
47
Service bulletins
Manufacturer communications
3
ODI investigations
Office of Defects Investigation
3
Owner complaints
0 involved a crash · 0 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Overall★★★★★
Frontal★★★★★
Side★★★★★
Rollover★★★★★
Owner complaints by model year NHTSA · this generation & adjacent
’11’12’13’14’15’16’17’18’19’20

Owner complaints filed with NHTSA, by component

All 3 complaints on record, top 3 components.

Engine1
Power Train,Unknown Or Other,Engine1
Electrical System,Engine,Fuel/Propulsion System1

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 2 campaigns on record for this vehicle.

21V844000EngineReported 29/10/2021

Kia Motors America (Kia) is recalling certain 2017-2018 Optima Hybrid and Optima Plug-In Hybrid vehicles. The connecting rod bearings inside the engine may wear prematurely, which can result in engine damage. Remedy: Dealers will inspect the engine. If bearing damage is found, the engine will be replaced. Dealers will also install a software update containing a Knock Sensor Detection System…

23V594000Latches/Locks/Linkages:Trunk Lid:LatchReported 24/08/2023

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… 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…

Technical service bulletins NHTSA · verified

Showing 5 of 47 bulletins on record with NHTSA.

BulletinDateComponentSummary
PS7972025-12-09Back Over PreventionPITSTOP: TECHNICAL OPERATIONS: EXTERNAL DAMAGE TO ULTRASONIC SENSOR: This Pitstop…
TSB_TRA046_R52025-04-17Power TrainTECHNICAL SERVICE BULLETIN: TRANSMISSION FLUID APPLICATION GUIDE - This bulletin has been…
TSB_TRA046_R42024-05-16Power TrainThis bulletin provides information relating to the correct transmission fluid type and…
TSB_CLI049_R12023-06-26Electrical SystemTECHNICAL SERVICE BULLETIN: PARTIAL REPAIR - ELECTRICAL A/C COMPRESSOR - This bulletin…
TSB_ELE192_R12023-01-18Electrical SystemTECHNICAL SERVICE BULLETIN: SERVICE ACTION: BMS/OPU/MCU LOGIC IMPROVEMENT (SA411) - This…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific Optima Hybrid. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Group 48 batteryVehicles taking 4.7 qt

Reference guides

Cross-vehicle references for the kinds of data on this page.

Vehicle recalls & TSBsOBD-II trouble codesTorque specificationsMaintenance schedulesFluid capacities & specs

Frequently asked

How much oil does the 2018 Optima Hybrid take?

4.7 qt of All temperatures: 5W-20 Preferred, 5W-30, Above 0 degreesF 10W-30., per the factory manual.

Does the 2018 Optima Hybrid have open recalls?

NHTSA lists 2 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the Optima Hybrid get?

EPA figures are 39 city / 46 highway / 42 combined mpg.