Kia Optima— Transmission Guide

Complete transmission type, fluid specification, and service interval data for every Kia Optima generation.

2016–2020

Optima — 2.4L NA (LX/EX trims)

Transmission

6-Speed Automatic

Code: 6AT

Fluid Specification

ATF (check OEM spec — many require brand-specific)

Service Interval

Every 30,000 miles

Engine

Theta II 2.4L GDI (G4KJ) — 2.4L — Direct Injection

Drivetrain Options

FWD

2016–2020

Optima — 1.6T (LX Turbo trim)

Transmission

7-Speed Dual-Clutch (DCT)

Code: 7DCT

Fluid Specification

Dual-clutch fluid (dry clutch — Kia/Hyundai DCT oil)

Service Interval

Every 40,000 miles

Engine

Gamma 1.6 T-GDI (G4FD) — 1.6L (Turbo) — Direct Injection

Drivetrain Options

FWD

2016–2020

Optima — 2.0T (SX / SXL trims)

Transmission

6-Speed Automatic

Code: 6AT

Fluid Specification

ATF (check OEM spec — many require brand-specific)

Service Interval

Every 30,000 miles

Engine

Theta II 2.0 T-GDI (G4KH) — 2L (Turbo) — Direct Injection

Drivetrain Options

FWD

Frequently Asked Questions

What transmission does a Kia Optima have?

The Kia Optima uses a 6-Speed Automatic (6AT). Depending on the model year and trim level, the exact transmission may vary — see the year-by-year breakdown above for full details.

What fluid does a Kia Optima transmission take?

The recommended transmission fluid is ATF (check OEM spec — many require brand-specific). Always verify with your owner's manual or dealership, as the correct fluid can vary by production year and transmission variant.

How often should I service the Kia Optima transmission?

The recommended service interval is every 30,000 miles. Severe driving conditions (towing, frequent stop-and-go, extreme temperatures) may require more frequent service. Regular transmission maintenance is one of the best ways to prevent costly repairs.

Use our transmission lookup tool to search by year, make, and model for any vehicle.

Tired of looking this up for every RO?

DASH automates transmission identification, fluid specs, and service menus inside DealerTrack — so your advisors never have to search again.

Learn about DASH →