KiaRio2018Overview/kia/rio/2018/base/

2018 Kia Rio

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

Body PASSENGER CARTransmission Automatic (S6)

The 2018 Kia Rio is a passenger car powered by a 3.7-quart engine requiring 5W-20, 5W-30, or 10W-30 oil, paired with an automatic (S6) transmission and achieving EPA ratings of 28 city/37 highway/32 combined mpg. With 27 total owner complaints—led by engine issues—and a single recall, this model year sits well below the model line’s historical peak of 227 complaints in 2001, suggesting that the 2018 Rio represents a period of relative stability in the nameplate’s long-term reliability record spanning 2000 to 2023.

Model year202320222021202020192018201720162015

Quick specs

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

Engine oil capacity3.7 qtOEM · verified
Engine oil type5W-20 / 5W-30 / 10W-30OEM · verified
Lug nut torque79-94 ft-lbsOEM · verified
EPA fuel economy28/37/32 mpgEPA · verified

Fitment & sizes

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

From the factory this vehicle uses a BCI w/ISG: 48; w/out ISG: 121R · w/ISG: 760 CCA; w/out ISG: 550 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 w/ISG: 48; w/out ISG: 121R · w/ISG: 760 CCA; w/out ISG: 550 CCAOEM · verified
Tail / brake / turnLAMPOEM · verified
Tire sizeP185/65R15OEM · verified
Wheel / rim5.5; Optional: 6.5 inOEM · verified

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic (S6)

Dimensions & weight NHTSA vPIC

Overall length172.8 in
Overall width68.1 in
Overall height57.1 in
Wheelbase101.6 in
Curb weight2648 lb
Track (front / rear)59.4 / 59.8 in
Weight distribution (front / rear)57/43

Ratings & economy EPA / vPIC

EPA city / highway / combined28 / 37 / 32 mpg
DrivetrainFront-Wheel Drive
Passenger volume90 cu ft
Cargo volume14 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 Rio of this era, listed by trim and engine — this page spans more than one engine, so no single horsepower figure is shown.

8.5–9.0 sec0–60 mph (tested)quickest 8.50 sec — 2018 EX 5-door Hatchback
YearTrim / engine0–60¼ mileHPDrivetrain
2018EX 5-door Hatchback 1.6L I-48.50 sec16.70 sec130 hpFWD
2018EX 5-door Hatchback 1.6L I-48.70 sec16.60 sec130 hpFWD
2018EX 5-door Hatchback 1.6L I-49.00 sec16.80 sec130 hpFWD
2021S 5-door Hatchback 1.6L I-48.60 sec16.80 sec120 hpFWD
2021S 5-door Hatchback 1.6L I-48.60 sec16.70 sec120 hpFWD

Service quick specs OEM factory data

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

This engine holds 3.7 qt of 5W-20 / 5W-30 / 10W-30 engine oil, DOT 3 brake fluid. Torque lug nuts to 65-79 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 Capacity7.1
Brake FluidDOT 3
Clutch FluidDOT 3
Engine CoolantEthylene Glycol
Engine Coolant Capacity5.7-6.0
Engine Oil5W-20 · 5W-30 · 10W-30
Engine Oil Capacity3.7 qt

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 Pulley and/or Damper Bolts109.0-116.0 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 Bolts14-17 ft-lbs

Chassis torques

Lug Nuts79-94 ft-lbs
Lug Nuts65-79 ft-lbs

Ignition

Cylinder Firing Order1-3-4-2
Spark Plug ManufacturerKia
Spark Plug GapNGK Plug:
Spark Plug Torque11-18 ft-lbs

Battery & A/C

RefrigerantR134a
Refrigerant Capacity.98-1.09 lbs.
Oil GroupPAG
Oil Type46
Oil Capacity3.72-4.40 oz.
Standard BCI Group Numberw/ISG: 48; w/out ISG: 121R
Standard BCI Cranking Performancew/ISG: 760 cca; w/out ISG: 550 cca

Service checks

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
RPM70

Brakes

Brake Caliper Bolt to Carrier Torque16-23
Brake Caliper Carrier to Hub Bolt Torque58-72
Vented Rotor Minimum Thickness for ReplacementFront: .787; Rear: .331
Variation from Parallelism Thickness Variation.0002
Maximum Rotor RunoutFront: .002; Rear: .001
Maximum Drum Diameter8.079 / Rear: 8.079

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
Cylinder Head — tightening sequence 3 stages
122 ft. lbs.22 ft. lbs
2Turn 90 degrees90 degrees
3Turn 90
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 every 97,500 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 miEngine Air Filter Element (inspect) · Engine Oil (drain & refill) · Engine Oil Filter (replace) · Fuel Tank (add fluid conditioner) · Tire & Wheel Assembly (rotate) · Vacuum Line (inspect)
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) · Clutch Master Cylinder (inspect fluid level) · Engine Coolant System (drain, flush & refill) · Fuel Evaporative Canister Filter (inspect) · Fuel Evaporative Emission Control System Lines (inspect) · Fuel Line (inspect)
Every 37,500 miTransmission Assembly (inspect fluid level)
At 60,000 miAccessory Drive Belt (inspect)
Every 60,000 miEngine Valves (inspect valve lash)
Every 97,500 miSpark Plugs (replace)
At 120,000 miEngine Coolant System (drain, flush & refill)

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 Rio sits in a favorable low-complaint phase of the federal record, posting 27 complaints, 1 recall, and 0 investigations, a sharp decline from the generation’s mid-record peak of 153 complaints and 2 investigations in 2013. Against its immediate neighbors, 2018 improves on 2017’s 31 complaints and 2 recalls yet carries slightly more complaints than 2019’s 21, while sharing the same single-recall, zero-investigation profile seen in 2019 and 2020. Engine complaints lead the 2018 filings with 9, though the data does not specify root cause, alongside 3 crash and 2 fire complaints. With 70 TSBs—consistent with 2017’s 65 and 2019’s 60—the year marks a settled point in the model’s downward trajectory from mid-decade highs. Given its low complaint volume, minimal recall count, and absence of investigations, 2018 is a strong year to buy within this federal record.

1
Open recalls
NHTSA campaigns
70
Service bulletins
Manufacturer communications
0
ODI investigations
Office of Defects Investigation
27
Owner complaints
3 involved a crash · 2 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Overall★★★★★
Frontal★★★★★
Side★★★★★
Rollover★★★★

Owner complaints filed with NHTSA, by component

All 27 complaints on record, top 8 components.

Engine9
Unknown Or Other3
Latches/Locks/Linkages2
Electrical System,Air Bags,Engine1
Electrical System,Air Bags1
Air Bags,Seats1
Structure1
Engine & Engine Cooling1

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 1 of 1 campaigns on record for this vehicle.

21V622000Latches/Locks/Linkages:Trunk Lid:LatchReported 09/08/2021

Kia Motors America (Kia) is recalling certain 2016-2018 Forte 4-door, Forte Koup 2-door, and 2018-2019 Rio 4-door vehicles. The trunk latch may become damaged, preventing the opening of the trunk from the inside. As… Remedy: Dealers will replace the trunk latch assembly, free of charge. Owner notification letters were mailed on February 10, 2022. Owners may contact Kia customer service at…

Technical service bulletins NHTSA · verified

Showing 5 of 70 bulletins on record with NHTSA.

BulletinDateComponentSummary
CS2311_TSB_R42026-06-08StructureTECHNICAL SERVICE BULLETIN: CUSTOMER SATISFACTION: THEFT DETERRENT IGNITION: CYLINDER…
CS2312_TSB_R22026-06-08StructureTECHNICAL SERVICE BULLETIN: CUSTOMER SATISFACTION: THEFT DETERRENT IGNITION CYLINDER…
TSB_CS2312_R12026-02-18StructureTECHNICAL SERVICE BULLETIN: CUSTOMER SATISFACTION: THEFT DETERRENT IGNITION CYLINDER…
CS2311_OWNR_PC2012025-12-19StructureCUSTOMER SATISFACTION CAMPAIGN: POSTCARD OWNER RENOTIFICATION (CS2311) - This document is…
TSB_CS23122025-12-17StructureTECHNICAL SERVICE BULLETIN: CUSTOMER SATISFACTION: THEFT DETERRENT IGNITION CYLINDER…

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 Rio. 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 Rio take?

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

Does the 2018 Rio have open recalls?

NHTSA lists 1 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the Rio get?

EPA figures are 28 city / 37 highway / 32 combined mpg.