“The Kia K5 had been a joy to own from the start. It is a great car that I would recommend anyone who is in the market to give it a honest look.”
2021 Kia K5: What's New, Specs & Features
Last updated August 4, 2026
The 2021 Kia K5 is an all-new midsize sedan that replaces the Optima in the U.S. It starts a new generation with a different name, platform, body, and overall design.
About the 2021 Kia K5
All-new DL3 generation, first US model year under the K5 name as the Optima successor.
Kia positions the K5 as a midsize sedan for shoppers who want family-car usefulness without a plain design. Its main draw is the dramatic fastback-like shape, turbo power across the lineup, strong standard driver-assistance features, and feature-rich value for the class. In plain terms, the K5 is the style-forward alternative to mainstream sedans like the Accord and Camry, with a quiet cabin, easy everyday manners, and a more athletic look than most rivals.
The 2021 lineup ranges from the value-focused LX to the comfort-oriented EX, which has synthetic leather, heated and ventilated front seats, and a panoramic sunroof. The GT-Line adds a sportier look while retaining the 180-hp engine, while the GT backs up its appearance with a 290-hp 2.5-liter turbo engine, larger brakes, and a sport-tuned suspension.
What changed, by category
Structural
The K5 moves to Kia’s new N3 platform with a longer, lower, and wider body. An acoustic laminated windshield is standard across the lineup to help reduce cabin noise.
Styling
The Optima’s traditional sedan shape gives way to the K5’s lower, wider, fastback-style body.
Powertrain
Every K5 uses a turbocharged engine. Most trims have a 180-hp 1.6-liter turbo four-cylinder, while the GT introduces a 290-hp 2.5-liter turbo four-cylinder and a performance-focused 8-speed automatic. AWD was offered on LXS and GT-Line versions.
Safety
Every trim has a broader standard safety package with forward collision braking, lane keeping, lane following, driver attention warning, and automatic high beams.
2021 Kia K5 specs and features by trim
| Feature | |||||
|---|---|---|---|---|---|
| Engine | 4-Cyl, Turbo, 1.6 Liter | 4-Cyl, Turbo, 2.5 Liter | 4-Cyl, Turbo, 1.6 Liter | 4-Cyl, Turbo, 1.6 Liter | 4-Cyl, Turbo, 1.6 Liter |
| Transmission | Automatic, 8-Spd | Automatic, 8-Spd Dual-Clutch | Automatic, 8-Spd | Automatic, 8-Spd | Automatic, 8-Spd |
| Drivetrain | FWD | FWD | FWD | FWD | FWD |
| Fuel Type | Gas | Gas | Gas | Gas | Gas |
| MPG City | 27 mpg | 24 mpg | 29 mpg | 27 mpg | 27 mpg |
| MPG Highway | 37 mpg | 32 mpg | 38 mpg | 37 mpg | 37 mpg |
| Horsepower | 180 hp | 290 hp | 180 hp | 180 hp | 180 hp |
| Torque | 195 lb-ft | 311 lb-ft | 195 lb-ft | 195 lb-ft | 195 lb-ft |
| Trunk/Cargo | 16 cu-ft | 16 cu-ft | 16 cu-ft | 16 cu-ft | 16 cu-ft |
| Rear Legroom | 35.2 in | 35.2 in | 35.2 in | 35.2 in | 35.2 in |
| Seats | 5 | 5 | 5 | 5 | 5 |
| Doors | 4 | 4 | 4 | 4 | 4 |
| Adaptive Cruise Control | |||||
| Blindspot Sensors | |||||
| Lane Departure Warning | |||||
| Rear Parking Sensors | |||||
| Rear View Camera | |||||
| Alloy Wheels | |||||
| Fog Lights | |||||
| LED Headlights | |||||
| LED Tail Lights | |||||
| Memory Exterior Mirrors | |||||
| Panorama Moon Roof | |||||
| Rear Spoiler | |||||
| Navigation System | |||||
| Premium Audio | |||||
| Satellite Radio | |||||
| Smartphone Interface | |||||
| Dual Power Front Seats | |||||
| Dual-Zone Climate Control | |||||
| Folding Rear Seat | |||||
| Rear Air Conditioning | |||||
| Heated Front Seats | |||||
| Heated Steering Wheel | |||||
| Leather-Wrapped Steering Wheel | |||||
| Memory Driver's Seat | |||||
| Power Driver Seat | |||||
| Proximity Keyless Entry | |||||
| Push-Button Engine Start | |||||
| Remote Start | |||||
| Ventilated Front Seats | |||||
Frequently asked questions
Is the 2021 Kia K5 the replacement for the Kia Optima?
Yes. The 2021 K5 replaces the Optima in the U.S. and begins an all-new generation with a new platform, body, and model name.
Is the 2021 Kia K5 a full redesign?
Yes. The 2021 K5 is a full redesign rather than a light update of the Optima. It uses Kia’s N3 platform and has a longer, lower, and wider fastback-style body.
Which 2021 Kia K5 trims have AWD?
AWD was offered on the 2021 K5 LXS and GT-Line. The LX, EX, and performance-focused GT are front-wheel drive, so it is important to verify the drivetrain on an individual LXS or GT-Line.
What is the difference between the 2021 K5 GT and GT-Line?
The GT is the performance model, while the GT-Line is mainly a sport-appearance trim. The GT has a 290-hp 2.5-liter turbo engine, larger brakes, and a sport-tuned suspension; the GT-Line uses the regular 180-hp 1.6-liter turbo engine.
What safety features are standard on every 2021 Kia K5?
Every 2021 K5 has forward collision braking, lane keeping, lane following, driver attention warning, and automatic high beams. Some higher trims add blind-spot and rear cross-traffic collision-avoidance features.
2021 Kia K5 Reviews
What owners are saying about the 2021 Kia K5.
4.3
2021 Kia K5
(242 reviews)
“I love my Kia K5 it has all the features of a luxury car. Everybody loves my car and it drives smooth even in sports mode. I came from a Dodge Charger but I love my K5 more!”
“Great looking car, well designed interior, good value for the money, good technology, and fun to drive!”