2021 Kia K5 Review

Christian Wardlaw, Independent Expert | Oct 22, 2020

Introduction - Find the best Kia deals!

The 2021 Kia K5 is a midsize sedan. It replaces the Optima in Kia's lineup, a vehicle that ranked high in the J.D Power 2020 Automotive Performance, Execution and Layout (APEAL) Study despite its advancing age. It also replaces the Optima nameplate, presumably derived from the word "optimum" and used for 20 years on vehicles that mostly did more than less to live up to that promise. 

As was true before, the new 2021 Kia K5 shares a platform, powertrains, and technology with the Hyundai Sonata, its corporate cousin. However, Kia puts its own spin on things with entirely different exterior styling and interior design, along with other details unique to this vehicle. It comes in LX, LXS, GT-Line, EX, and GT trim levels, and prices start at $23,490, not including a destination charge of $965.

2021 Kia K5 front view

Photo: Christian Wardlaw

For this review, J.D. Power evaluated a Kia K5 EX equipped with the EX Premium Package, a cargo mat, and floor mats. The price came to $32,605, including the destination charge.

What Owners Say… - Find the best Kia deals!

Before we discuss the results of our evaluation of the 2021 Kia K5, it is helpful to understand who bought the previous Kia Optima and what they liked most and least about their vehicles.

According to J.D. Power data, 52% of Kia Optima owners are male (vs. 60% for the segment), and the median age of an Optima owner is 52 years (vs. 55).

Owners say their favorite things about the Optima were (in descending order) the exterior styling, driving feel, feeling of safety, interior design, and fuel economy. Specifically, these five things about the vehicle ranked highest in comparison to the midsize car segment:

  • Getting in and out of the front seats
  • Usefulness of other infotainment functions
  • Exterior styling
  • Ability to hold personal items
  • Safety systems and getting vehicle set up (in a tie)

Owners indicate their least favorite things about the Optima were (in descending order) the driving comfort, powertrain, getting in and out in a tie with setting up and starting, and the infotainment. Specifically, these five things about the vehicle ranked lowest in comparison to the midsize car segment:

  • Fuel economy/driving range
  • Vehicle feel when started up
  • Effectiveness of headlights
  • Vehicle protection
  • Smoothness of engine/motor and audio system sound quality (in a tie)

In the J.D Power 2020 Automotive Performance, Execution and Layout (APEAL) Study, the Optima ranked 3rd out of 10 midsize cars.

What Our Expert Says… - Find the best Kia deals!

In the sections that follow, our independent expert provides his perceptions about how the 2021 Kia K5 measures up in each of the ten categories that comprise the APEAL Study.


For a decade now, Kia's midsize sedan has been a style leader in its segment. That doesn't change with the 2021 Kia K5, which in EX specification looks more like a luxury car than a traditional family sedan.

2021 Kia K5 EX Gravity Gray Rear Quarter View

Photo: Christian Wardlaw

Heartbeat lighting elements give the car an unmistakable look, and the Gravity Gray paint sparkles in the sunlight. A fastback roofline suggests a rear hatch's added utility like Kia's own Stinger, but the K5 gets a roomy trunk instead. Upgrade to GT-Line or EX trim for larger aluminum wheels with a machined outer finish.

For a performance appearance, the GT-Line and GT trim levels feature more aggressive-looking front and rear bumpers. Kia sets the high-powered GT apart with exclusive 19-inch wheel designs.


While the Kia K5 EX's leatherette upholstery and simulated wood trim are not the real deal, it's tough to tell the difference. Combined with the metallic accents throughout the interior, the creative detailing around the air vents, and the aircraft-inspired transmission shifter, the K5's cabin makes you feel like you spent more on this car than you did. That's a good thing, and it goes a long way toward making owners happy with their purchase.

2021 Kia K5 EX Ash Blue Seats Dashboard

Photo: Christian Wardlaw

Kia backs up the appearance of quality with robust construction and soft-touch materials in the places where it matters the most. For example, as has been true of Kias for a long time, when you use the transmission shifter, it feels solid and secure instead of loose and sloppy, conveying a sense of quality and attention to detail with every single drive. Secondary materials, such as the plastic on the lower door panels and sides of the center console, meet expectations for the segment.

Storage impresses, and, similar to the Sonata, the door panel armrests frame a handy slot for smaller items. The control layout is intuitive, too, but the widescreen infotainment display takes a couple of steps backward because it lacks a radio tuning knob and replaces physical menu shortcut buttons with touch-sensitive plastic that doesn't always respond to input.

Getting In and Out

Built on a new vehicle platform that positions the K5's cabin closer to the ground, this low-slung sedan isn't as easy to get into and out of as, say, the redesigned 2021 Kia Sorento

However, with EX trim and the optional Premium package, both the driver's seat and the front passenger's seat are height-adjustable, which means you can improve the hip-point and make entry and exit easier if you prefer. Also, the rear doors open wide, and the K5 offers generous rear legroom, so climbing into and out of the back seat is relatively effortless.

All Kia K5s except for LX trim have a hands-free Smart Trunk opener. Simply stand behind the car with the key for a few seconds, and it will open automatically. Alternatively, you can push a button on the lid or use the key fob for popping the trunk.

When you do so, the lid opens all of the way up. This action is super helpful when your hands are full. Inside, the cargo area measures 16 cubic feet, making it among the more generously proportioned trunks in the midsize car class.

Setting Up and Starting

It's been a long time since I felt a need to refer to an owner's manual to determine how to set up an infotainment system, but the Kia K5 inspired precisely that activity. 

The problem was unrelated to using the different menus to choose preferences and vehicle settings – that's a fairly straightforward endeavor. Instead, I sought a way to change the system's colors and theme, a quest that resulted in as much frustration as trying to navigate Kia's consumer website.

Kia delivered the K5 test vehicle with the infotainment system's "Home" screen showing the time and date to the extreme left and a faint, barely visible representation of the car's current position on a map to the extreme right. In between was a blank canvas, tinted purple.

"Certainly," I thought to myself, "there must be a way to program this so that three different data panels clearly show the radio, the navigation map, and the phone connection." Continuing with this inward discussion: "And I can't stand the weird purple graphics on the menu pages when I swipe right from the purplish Home screen. If Prince couldn't make me like that color, Kia doesn't stand a chance."

Alas, after going through the owner's manual and all of the system settings, there appears to be no way to achieve either objective. Since every Kia-sourced image of the infotainment system that I can find shows either the purple-themed screen you get when you swipe right from Home or the Apple CarPlay interface, this must be true. Sure, you can arrange all of those purple icons in whatever manner you choose, but I never discovered a way to alter programming for what shows on the default Home display.

Aside from my personal issues with the infotainment system's graphics, layout, and customization options, the K5's appealing interior design and detailing makes a driver eager to push the engine-start button and get on the road.

Infotainment System

Though I found the test K5's 10.25-inch touchscreen infotainment system to be graphically unappealing, it doesn't lack for features. 

In addition to a navigation system, the test car included Apple CarPlay and Android Auto, a Wi-Fi hotspot, and Kia UVO Link connected services, including 911 Connect. Mostly I listened to SiriusXM satellite radio, the channel numbers curiously expressed in what appear to be graphic representations of classic vacuum tubes. Or old-timey light bulbs. Either way, it's strange.

I had no trouble pairing to Bluetooth, wirelessly streaming music, switching between media sources, or using the natural language voice recognition technology. The infotainment system includes a button with a star on it that you can program for quick access to a feature or function you use regularly, and the Sounds of Nature relaxation tracks were a hit with my family. It plays six different nature sounds to help you chill out and relax.

Also, unlike my sentiments with similar components in the Hyundai Sonata, the 12-speaker Bose premium sound system in the K5 sounded decent and had stylish speaker covers.

Though fundamentally up to expectations for the segment, the K5's infotainment system left me wanting. For a tuning knob. For different colors. For a more conservative expression of the data. For physical rather than touch-sensing menu shortcuts surrounding the screen. And for larger virtual radio station pre-set buttons on the screen.

Keeping You Safe

Every 2021 K5 is equipped with a standard Kia Drive Wise collection of advanced driving assistance systems (ADAS). They include forward-collision warning with pedestrian detection, automatic emergency braking, lane-departure warning, lane-keeping assistance, lane-centering assistance, a driver attention monitor, and automatic high-beam headlights. A rear-seat reminder system is also standard.

Additionally, the K5 has a Leading Vehicle Departure Alert system that is perfect for modern times. If you're sitting at a red traffic light scrolling through email or social media, and the light turns green, and the vehicle ahead starts to move, this feature will sound a chime to get your attention so that you won't hold up traffic any longer than you already have.

With LXS trim, the K5 adds blind-spot warning and rear cross-traffic warning, as well as a Safe Exit Assist system that alerts occupants when traffic is approaching from behind so they won't open the doors and try to exit the car when it is unsafe. With EX and GT trim, this function includes a power door lock function to prevent children from ignoring the alert.

Starting with GT-Line trim, the K5 supplies cyclist detection, junction-turning assistance, adaptive cruise control with stop-and-go capability, and Highway Driving Assist. Junction-turning assistance is a relatively rare feature regardless of vehicle price, and it automatically brakes the K5 if the driver attempts an unsafe left turn across oncoming traffic. Most people will experience it when taking a left on a yellow light as an approaching vehicle tries to beat their red light.

Highway Driving Assist is a Level 2 driving assistance system and is remarkably good at any price point, let alone a mainstream Kia's. Smooth, accurate, and refined, it also works for quite some time before requesting that a driver return his or her hands to the steering wheel. However, this is not a hands-free technology similar to Cadillac Super Cruise. You are expected to hold the steering wheel at all times.

As we published this review, the Kia K5 had not been subjected to crash tests.


If you want power and performance, get a Kia K5 GT. It's got a turbocharged 2.5-liter 4-cylinder engine good for a mighty 290 horsepower at 5,800 rpm and 311 lb.-ft. of torque between 1,650 rpm and 4,000 rpm. An exclusive 8-speed wet dual-clutch automated manual transmission is standard with this power plant, which drives the car's front wheels.

All other K5s have a turbocharged 1.6-liter 4-cylinder engine. While it is not nearly as powerful as what's under the GT's hood, it delivers enough torque to make the K5 feel lively in everyday driving situations. It produces 180 hp at 5,000 rpm and 195 lb.-ft. of torque between 1,500 rpm and 4,500 rpm, and pairs with an 8-speed automatic transmission. The car is front-wheel drive unless you've specified the optional all-wheel-drive system.

The K5 EX generates enough off-the-line thrust to spin the front tires and cause the traction control to activate. However, the engine seems to run out of steam fairly soon, and the passing power at higher speeds is merely adequate. Most of the time, for most of your driving, this engine delivers just the right amount of acceleration and responsiveness for your needs while emitting a pleasing note.

Smart, Normal, Sport, and Custom driving modes calibrate the car's behavior, and with all-wheel drive, the K5 has a Snow mode. I mainly used Smart and Sport modes. In Smart mode, there is usually a delay when you request more power while the drivetrain sorts out what to do. In Sport mode, this is less evident, but there can still be a momentary delay when stepping on the gas after exiting a turn.

Drivers can take manual control of the transmission by moving the shifter to the left into a separate gate. Intuitively, you push the shifter up to execute an upshift and down to perform a downshift. Manually shifting helps keep the engine in the thick of its torque curve and ready to respond, but the shifter is snug against your leg when in manual mode. Kia does not offer steering wheel paddle shifters with this engine and transmission.

Fuel Economy

The EPA offers optimism when it comes to the Kia K5's fuel economy estimates. 

It says the car should get 31 mpg in combined driving, but on the test loop, my K5 test car averaged 28.6 mpg. Keep in mind that I switched between Smart, Normal, and Sport modes during portions of the drive and used manual mode for a short stretch of mountain driving.

With the K5's 15.8-gallon gas tank, my result suggests that the car will travel more than 450 miles on a full load of fuel. You'll probably stop at the gas station every 400 miles or so, but that's still a generous number.

Driving Comfort

There is plenty of room inside of the Kia K5, and with a low 0.27 coefficient of drag and an acoustic laminated windshield, the cabin is mostly free of wind and engine noise. Road noise, however, can be bothersome at times.

Featuring soft, perforated leatherette upholstery that is remarkably convincing as the real thing, as well as heated and ventilated front seats with 10-way power adjustment, the K5 EX with the Premium Package promises comfort. 

Still, I had a hard time finding a good driving position in this car. I prefer to sit up high, but with the seat positioned the way I wanted it, the low-slung roof caused my hair to touch the headliner. So, I had to find a lower position, but then I wasn't crazy about the relationship between my elbows and the center console and door armrests or between my body and the tilt-and-telescopic steering wheel. After quite a bit of trial and error, I finally settled on a position.

Rear seat room is generous, and the bottom cushion is supportive. I thought the backrest angle offered too much recline, though, promoting slouching. 

Temperate fall weather during testing taxed neither the heating nor the air conditioning systems. It is worth noting that Kia provides rear air conditioning vents only with EX and GT trim.

Driving Feel

Just as Kia tunes the K5 EX's engine for everyday driving, so too is the car's ride and handling. 

Kia uses a MacPherson strut front and multi-link rear suspension design for the K5, tuned for soft compliance but without unnecessary body motions. The car handles speed humps at 25 mph, and it softens and isolates road impacts from potholes and broken pavement. Yet, it simultaneously maintains clear lines of communication regarding the road surface. 

Kia reserves firmer suspension settings and a rack-mounted electric steering system for the high-powered K5 GT. Other K5s employ less-ideal column-mounted electric steering assist. Still, it demonstrates proper weight and consistent response in Smart and Normal modes even if it lacks crispness and clarity. The brake pedal feels perfectly natural underfoot and is a useful tool in any driving situation.

The test car wore P235/45R18 Pirelli P Zero all-season tires, and they proved to be the weakest link in the handling equation. No doubt due in part to the K5's 60:40 front-to-rear weight distribution, they howl early, and the nose pushes in tight curves and corners. Still, the K5's handling character is exceptionally predictable, making the car tossable and trustworthy within the scope of its grip.

Final Impressions - Find the best Kia deals!

If you count the Stinger, which is actually a 5-door sportback, Kia sells six different sedans. Undoubtedly, the company is trying to decide what to do about this situation, considering that consumers don't buy 4-door cars like they used to.

With its new name, new design themes, and new engineering, the 2021 Kia K5 won't get cut from the roster. And that's not just because of the investment Kia has made in the car. The K5 has the right mix of style, size, sophistication, safety, and value to remain on the radar of people who still prefer family-sized cars to compact SUVs.

They just need to remember to Google "Kia K5" instead of "Kia Optima" when performing their research. And it won't be cheap for Kia to remind them of it regularly.

Christian Wardlaw is a veteran digital automotive journalist with over 25 years of experience in test-driving vehicles. In addition to JDPower.com, his work has appeared in numerous new- and used-car buying guides, newspapers, and automotive industry trade journals.

The opinions expressed in this review are the author’s own, not J.D. Power’s.

No portion of these reviews may be reproduced, distributed, publicly displayed, or used for a derivative work without J.D. Power’s written permission. © 2023 J.D. Power

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