“The 2021 Kia K5 goes big on style and sportiness, without sacrificing practicality.”
- Attractive styling
- Powerful engine
- Nimble chassis
- Intuitive tech
- Low level of standard driver-assist tech
Kia spent two decades transforming the Optima midsize sedan from a joke into a genuinely desirable car — all so it could rebrand and start anew.
The 2021 Kia K5 is the replacement for the Kia Optima. While the name is a sterile alphanumeric combination that car buyers are more likely to associated with a Chevy SUV than anything wearing the Kia badge, the K5 looks pretty good on paper. The last Optima was a good-looking car, but Kia dialed things up even further this time, while adding a bigger touchscreen, more driver-assist tech, optional all-wheel drive, and a sporty GT model.
Kia needs to pull out all of the stops if it wants buyers’ attention. The K5 has many rivals, including the Honda Accord, Toyota Camry, Nissan Altima, Mazda 6, Subaru Legacy, and Volkswagen Passat, as well as its sibling — the Hyundai Sonata.
Pricing for the 2021 Kia K5 starts at $24,555 (all prices include a mandatory $965 destination charge), but that only buys an entry-level LX model. Our test car was the range-topping K5 GT, with a more powerful engine and sport-tuned suspension. The GT starts at $31,555, but our test car also had the optional GT1 package, which adds a 10.25-inch touchscreen, Bose premium audio system, and adaptive cruise control, among other features. That brought the MSRP to $35,705.
Design and interior
The K5 shares a basic platform with the Hyundai Sonata, but designers did a good job of distinguishing the two. Where the Hyundai has smooth lines that make it seem like it’s floating along the road, the K5 is a bit more muscular, with a bulging hood and a front bumper that juts forward like the chin of a 1940s comic book character. That’s in line with both sedans’ personalities. The Hyundai is a laid-back cruiser, while the K5 is meant to be sportier.
However, the main distinguishing feature of the K5 is lighting. At the front, you get squiggly LED daytime running lights Kia calls the “Heart Beat,” plus a horizontal light blade across the back. While the overall shape of the K5 is very sleek and attractive, many other sedans have a similar shape these days. Styling is subjective, but the lighting design makes the K5 a lot more distinctive.
Sleek styling normally comes at the price of interior space, but that isn’t the case with this Kia. The K5 has more front headroom and legroom than other midsize sedans and only 0.2 cubic feet less rear headroom than the class-leading Toyota Camry. However, rear legroom is a bit below average.
Styling is subjective, but the lighting design makes the K5 a lot more distinctive.
At 16 cubic feet, trunk space is above average, but behind the 16.7 cubic feet of the class-leading Honda Accord. The K5’s Hyundai Sonata sibling also offers a smidge more cargo space, at 16.3 cubic feet. Kia also offers a 60/40 split-folding rear seat to accommodate longer items, but that feature isn’t available on the base K5 LX trim level.
The interior design was clean and functional, although the slope of the roof hampered rearward visibility somewhat. Our K5 GT test car had niceties like heated and ventilated front seats, a heated steering wheel, a driver’s memory system for the seat and mirrors, and a panoramic sunroof, proving Kia still takes its reputation as a value brand seriously. Materials didn’t feel very high-end (Kia only offers leatherette, rather than real leather upholstery), but were acceptable given the car’s price tag. However, Kia used a lot of shiny plastic that created a distracting glare on sunny days.
Tech, infotainment, and driver assist
The standard infotainment system includes an 8.0-inch touchscreen, but you can get a 10.25-inch touchscreen as an upgrade. Oddly, Kia offers wireless Apple CarPlay and Android Auto only with the smaller screen. While you’ll still need to plug into to use CarPlay and Android Auto on the larger screen, but it does add natural-language voice recognition and multi-connection Bluetooth.
Our test car had the optional 10.25-inch screen, which featured cool-looking graphics, including old-fashioned radio tubes for radio stations. We appreciated the shortcut buttons for different menus but found the buttons on the right side of the screen a bit hard to reach from the driver’s seat. The voice-recognition system — which is designed to recognize simple phrases like “turn on the air conditioning” — didn’t have any apparent comprehension issues but was a bit slow to respond.
Wireless phone charging is also available, with an unusual design that involves dropping the phone into a vertical slot. That seems like a clever way to save space, but Kia still left a phone-sized cubby — without charging — ahead of the shifter.
The bigger optional touchscreen featured cool-looking graphics, including old-fashioned radio tubes for radio stations.
Also available is a 12-speaker Bose audio system with subwoofer and external amplifier. If you get sick of listening to music, Kia also provides “sounds of nature,” including “lively forest,” “calm sea waves,” “rainy day,” “warm fireplace,” and “open-air café” sounds that turn the K5 into a white-noise machine on wheels.
Standard driver-assist tech under the Kia Drive Wise banner includes forward-collision warning, automatic emergency braking, a driver-attention monitor, and Lane Follow Assist automated lane centering. Optional features include blind-spot monitoring, rear cross-traffic alert, reverse automatic braking, and adaptive cruise control. The latter can use the navigation system to preemptively lower speed for highway curves or changes in the speed limit.
On the highway, the adaptive cruise control accelerated and decelerated smoothly, although we didn’t have an opportunity to test out the automated speed-limit adjustment feature. The system also has a stop-and-go function, which is handy in heavy traffic. However, it’s worth noting that several competitors — including the Honda Accord, Subaru Legacy, and Toyota Camry — offer adaptive cruise control as standard equipment, albeit without some of the features of Kia’s system. We also found Kia’s Lane Follow Assist to be less proficient than the lane-centering function of Subaru’s EyeSight system —–which isn’t exactly perfect, either.
The standard powertrain is a 1.6-liter turbocharged four-cylinder engine, which produces 180 horsepower and 195 pound-feet of torque. The engine is coupled to an eight-speed automatic transmission, with standard front-wheel drive or optional all-wheel drive. Those are respectable specs for an entry-level powertrain in a midsize sedan, and the availability of all-wheel drive is a perk for new-car buyers in colder climates. Note that you can also get all-wheel drive on the Nissan Altima and Toyota Camry, and it’s standard on the Subaru Legacy.
Kia K5 GT models like our test car get a 2.5-liter turbo-four, producing 290 hp and 311 lb-ft, with an eight-speed dual-clutch transmission for quicker shifts. The GT is only available with front-wheel drive, but Kia claims it will do zero to 60 mph in 5.8 seconds. That’s pretty quick for a mainstream sedan.
Most midsize sedans make you look like an adult. This one makes you look like a hooligan.
Kia did more than pack on the power, though. The GT gets a model-specific suspension setup for better handling and 19-inch wheels with high-grip Pirelli P-Zero tires. Even with those tires, though, the GT was powerful enough to spin its wheels on command. The “Sport+” drive mode also deactivates the traction control and lets the engine stay at its boiling point without upshifting. That’s not the kind of behavior you’d normally expect from a car like this. Most midsize sedans make you look like an adult. This one makes you look like a hooligan.
Things won’t get completely out of control, though. The K5 is more than theatrics; it’s got the moves to back up its bravado. Many modern cars feel like they’re violating the laws of physics when going around corners, but the K5 felt light and eager, like it actually wanted to move. That excellent chassis tuning was let down by numb steering, but the K5 is far from the only sporty car with that problem. The ride was also a bit harsh, but reasonable given the handling benefit of this suspension setup.
Gas mileage and safety
The most fuel-efficient 2021 Kia K5 model is the base LX with the 1.6-liter engine and front-wheel drive, which gets fuel-economy ratings of 32 mpg combined (29 mpg city, 38 mpg highway). Other models with the 1.6-liter engine get 31 mpg combined (27 mpg city, 37 mpg highway) with front-wheel drive, and 29 mpg combined (26 mpg city, 34 mpg highway) with all-wheel drive. The 2.5-liter GT is rated at 27 mpg combined (24 mpg city, 32 mpg highway), and we managed 26.4 mpg, according to the car’s trip computer.
Fuel-economy ratings are respectable for a midsize sedan, but it’s worth noting that that the Honda Accord, Hyundai Sonata, and Toyota Camry are all available with more-efficient hybrid powertrains. Kia previously offered an Optima Hybrid but hasn’t discussed plans for a hybrid K5.
The K5 received a “Top Safety Pick+” rating from the Insurance Institute for Highway Safety (IIHS), with top “Good” scores in all crash tests, and the top “Superior” score for front-crash prevention tech. However, headlight ratings ranged from “Good” to “Poor,” depending on trim level.
The National Highway Traffic Safety Administration (NHTSA) gave the 2021 K5 a five-star overall safety rating, with four stars in frontal and rollover crash tests, and five stars in side crash tests.
Kia offers a 10-year, 100,000-mile, powertrain warranty and a five-year, 60,000-mile, limited warranty. Those remain the longest warranty terms in the business. They’re unmatched by rivals except, of course, the Hyundai Sonata, from Kia’s sibling brand.
How DT would configure this car
The driving experience is really what sets the K5 apart from other midsize sedans, so we’d go for a GT model like our test car. While it’s a big step up from the base LX trim level, the GT is still a good value considering the amount of equipment you get, including a 290-hp engine, a well-tuned chassis, and plenty of creature comforts.
However, Kia presents a dilemma to tech-savvy buyers. Wireless Apple CarPlay and Android Auto are only available with the smaller 8.0-inch touchscreen, while the optional 10.25-inch touchscreen gets multi-phone Bluetooth pairing and natural-language voice recognition. So buyers have to decide which features they think are more important.
We didn’t get to test out the smaller screen, but considering that the larger screen is bundled with a $4,100 option package, we’d think long and hard about skipping it and saving a big chunk of change. While we liked the voice-recognition system, ditching cables seems like a bigger convenience boost.
The 2021 Kia K5 takes the solid foundation of the Optima and adds an extra dose of style and performance. It’s a well-executed midsize sedan, but it also faces strong competition.
The Honda Accord, Mazda 6, and even the once-bland Toyota Camry all offer satisfying driving experiences, while the Subaru Legacy has more standard driver-assist tech and a larger available touchscreen than the Kia, plus standard all-wheel drive. However, Kia still manages to stand out with a longer warranty and impressive value. Even with an option package tacked on, our K5 GT test car rang up at less than $40,000.
There’s also the matter of the Kia’s sibling—the Hyundai Sonata. The Hyundai gets tech that isn’t available on the Kia, including Remote Smart Parking Assist automated parking, a digital key function that lets you use a smartphone as a key, and a hybrid powertrain. However, the Sonata isn’t as entertaining to drive as the Kia. Hyundai does have a Sonata N-Line performance model, but a 2019 prototype drive left us underwhelmed.
Should you get one?
Yes. The K5 proves even ordinary, practical cars can be fun.