KiaNIRO DE HEV2018Overview/kia/niro-de-hev/2018/base/

2018 Kia NIRO DE HEV

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

Body SUVTransmission Automatic (AM6)

The 2018 Kia Niro is a compact SUV built on Kia’s dedicated hybrid platform and powered by a gasoline‑electric drivetrain paired with a 4.0‑quart oil capacity that accepts 0W‑20, 5W‑20, or 5W‑30 viscosity grades, while its AM6 automatic transmission delivers the class‑leading EPA ratings of 51 mpg city, 46 mpg highway and 49 mpg combined. Across the model line, owners reported a total of 56 complaints, with the power‑train identified as the most frequent trouble spot and three recalls issued, situating the 2018 Niro within a relatively modest complaint environment. Although the detailed yearly complaint data in the record begins in 2021—showing a peak of 40 complaints in 2023 and a low of eight in 2024—the 2018 model’s modest overall issue count suggests it occupies a stable position in the Niro’s broader reliability trajectory.

Model year20252023202220212020201920182017

Quick specs

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

Engine oil capacity4.0 qtOEM · verified
Engine oil type0W-20 / 5W-20 / 5W-30OEM · verified
Lug nut torque79-94 ft-lbsOEM · verified
EPA fuel economy51/46/49 mpgEPA · verified

Fitment & sizes

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

Tire sizeP205/60R16OEM · verified
Wheel / rim6.5 inOEM · verified

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic (AM6)

Dimensions & weight NHTSA vPIC

Overall length171.7 in
Overall width70.9 in
Overall height60.6 in
Wheelbase106.3 in
Curb weight3166 lb
Track (front / rear)61.8 / 62.2 in
Weight distribution (front / rear)54/46

Ratings & economy EPA / vPIC

EPA city / highway / combined51 / 46 / 49 mpg
DrivetrainFront-Wheel Drive
Passenger volume101 cu ft
Cargo volume22 cu ft
Recommended fuelRegular Gasoline

Performance & power Independent road tests

0–60 mph, quarter-mile, horsepower and torque from independent road tests.

Independent road tests for the Niro of this era, listed by trim and engine — this page spans more than one engine, so no single horsepower figure is shown.

9.0 sec0–60 mph (tested)quickest 9.00 sec — 2018 EX Premium EcoPlug-in Hatchback
YearTrim / engine0–60¼ mileHPDrivetrain
2018EX Premium EcoPlug-in Hatchback 1.6L I-4 + Elec 8.9-kWh9.00 sec17.00 sec139 hpFWD
2017FE EcoHybrid Hatchback 1.6L I-4 + Elec 32-kW 1.56-kWh8.60 sec16.70 sec139 hpFWD
2017LX EcoHybrid Hatchback 1.6L I-4 + Elec 32-kW 1.56-kWh8.70 sec16.80 sec139 hpFWD
2017EX EcoHybrid Hatchback 1.6L I-4 + Elec 32-kW 1.56-kWh8.90 sec16.80 sec139 hpFWD
2017Touring EcoHybrid Hatchback 1.6L I-4 + Elec 32-kW 1.56-kWh9.60 sec17.30 sec139 hpFWD
2017Touring EcoHybrid Hatchback 1.6L I-4 + Elec 32-kW 1.56-kWh9.60 sec17.20 sec139 hpFWD
2017Touring EcoHybrid Hatchback 1.6L I-4 + Elec 32-kW 1.56-kWh9.90 sec17.40 sec139 hpFWD
2017Touring EcoHybrid Hatchback 1.6L I-4 + Elec 32-kW 1.56-kWh10.10 sec17.70 sec139 hpFWD

Service quick specs OEM factory data

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

This engine holds 4.0 qt of 0W-20 / 5W-20 / 5W-30 engine oil, DOT 4 brake fluid. Torque lug nuts to 65-80 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 FluidGL-4
Automatic Transmission Fluid Capacity1.8
Brake FluidDOT 4
Engine CoolantEthylene Glycol
Engine Oil0W-20 · 5W-20 · 5W-30
Engine Oil Capacity4.0 qt
Power Steering FluidEPS

Engine torques

Crankshaft Position (CKP) Sensor Bolt(s)7.2-8.7 ft-lbs
Camshaft Position (CMP) Sensor Bolt(s)5.8-8.7 ft-lbs
Engine Coolant Temperature (ECT) Sensor Bolt(s)21.7-28.9 ft-lbs
Oxygen (O2S) Sensor Bolt(s)28.9-36.2 ft-lbs
Knock Sense (KS) Bolt(s)13.7-17.4 ft-lbs
Engine Flywheel Bolts53.0-56.0 ft-lbs
Intake Manifold to Engine Bolts13.7-17.4 ft-lbs
Exhaust Manifold to Cylinder Head Bolts25-29 ft-lbs

Chassis torques

Lug Nuts79-94 ft-lbs
Lug Nuts65-80 ft-lbs

Ignition

Cylinder Firing Order1-3-4-2
Curb Idle Speed (No Load)630 rpm
Curb Idle Speed Variance (No Load)100 rpm
Curb Idle Speed (Secondary Under Load)700 rpm
Curb Idle Speed Variance (Secondary Under Load)100 rpm

Battery & A/C

RefrigerantR134a
Refrigerant Capacity1.15-1.30 lbs
RefrigerantR134a
Refrigerant Capacity1.15-1.27 lbs.
Oil GroupPOE
Oil Capacity4.23-4.93 oz.

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

Brakes

Brake Caliper Bolt to Carrier Torque16-23
Brake Caliper Carrier to Hub Bolt TorqueFront: 72-; Rear: 47-
Brake Caliper Bolt to Carrier Torque16-23
Brake Caliper Carrier to Hub Bolt TorqueFront: 72-; Rear: 47-
Vented Rotor Minimum Thickness for ReplacementFront: .787; Rear: .330
Variation from Parallelism Thickness VariationFront: .0002; Rear: .0004
Maximum Rotor RunoutFront: .0016; Rear: .002
Vented Rotor Minimum Thickness for ReplacementFront: .787; Rear: .330

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
Connecting Rod (Large End) Bearings — tightening sequence 2 stages
113.0-16.0 ft. lbs.13–16 ft. lbs
290.0
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
148.0-53.0 ft. lbs., Step 2: 39-4148–53 ft. lbs
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
19.4-12.3 ft. lbs.9.4–12.3 ft. lbs
2Turn 120-125 degrees120–125 degrees
3Turn 120-125
Cylinder Head — tightening sequence 3 stages
19.4-12.3 ft. lbs.9.4–12.3 ft. lbs
2Turn 120-125 degrees120–125 degrees
3Turn 120-125
Main Bearings — tightening sequence 2 stages
113.0-16.0 ft. lbs.13–16 ft. lbs
290.0
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

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 7,500 mi; spark plugs at 105,000 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 7,500 miAccessory Drive Belt (inspect) · Engine Air Filter Element (inspect) · Engine Oil (drain & refill) · Engine Oil Filter (replace) · Fuel Tank (add fluid conditioner) · Tire & Wheel Assembly (rotate)
Every 15,000 miAir Conditioning System (inspect) · Brake Line (inspect) · Brake Linings (inspect) · Brake Rotor (inspect) · CV Joint Boot (inspect) · Cabin Air Filter (replace)
Every 22,500 miClutch Hydraulic System (drain & refill)
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 60,000 miDrive Belt (replace)
At 105,000 miSpark Plugs (replace)
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 Kia Niro's federal record, tracked from 2021 onward, reveals a clear arc: complaints surged from 9 in 2021 to a peak of 40 in 2023, then dropped to 13 by 2025, while recalls held steady at one per year except for a spike to two in 2023. This pattern suggests that age-related issues, particularly in the power train (15 complaints) and engine (7), became prominent as the vehicle reached the 5- to 7-year mark, though the data does not specify root causes. Technical service bulletins (TSBs) declined sharply from 52 to 10 over the same period, indicating that many fixes were identified and communicated early. The 2018 model year sits at the older end of this trend, and while recent complaint volumes are lower, the earlier concentration of power train and engine complaints—including four crash-related reports—signals a higher risk of mid-life mechanical problems. A pre-purchase inspection verifying completion of all recalls and relevant TSBs is essential; otherwise, the 2018 Niro represents a somewhat elevated risk compared to later model years with fewer accumulated complaints.

3
Open recalls
NHTSA campaigns
92
Service bulletins
Manufacturer communications
1
ODI investigations
Office of Defects Investigation
56
Owner complaints
4 involved a crash · 0 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Rollover★★★★★
Owner complaints by model year NHTSA · this generation & adjacent

Owner complaints filed with NHTSA, by component

All 56 complaints on record, top 8 components.

Power Train15
Engine7
Electrical System5
Unknown Or Other4
Service Brakes4
Electrical System,Engine3
Structure2
Electrical System,Unknown Or Other,Engine2

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

No recall campaigns on record with NHTSA for this vehicle as of the last data refresh.

Technical service bulletins NHTSA · verified

Showing 5 of 92 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_ENG222_R82025-04-03EngineTECHNICAL SERVICE BULLETIN: EXCESSIVE OIL CONSUMPTION NU/GAMMA/THETA/KAPPA ENGINES - This…
TSB_ENG222_R72025-02-28EngineTECHNICAL SERVICE BULLETIN: EXCESSIVE OIL CONSUMPTION NU/GAMMA/THETA/KAPPA ENGINES - This…
TSB_TRA046_R42024-05-16Power TrainThis bulletin provides information relating to the correct transmission fluid type and…

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 Niro. 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.

Reference guides

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

Frequently asked

How much oil does the 2018 Niro take?

4.0 qt of 0W-20, 5W-20, 5W-30 all temperatures, per the factory manual.

Does the 2018 Niro have open recalls?

NHTSA lists 3 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the Niro get?

EPA figures are 51 city / 46 highway / 49 combined mpg.