2025 Kia K4

We already have the Kia K5, an excellent midsize sedan that replaced the Optima. Now here’s the K4 compact sedan. It replaces the venerable Kia Forte, perhaps the last of the old-guard Kia cars that were not exactly adventurous from a styling point of view.

That all changes with the Kia K4, which has sharp exterior styling that simply cannot be ignored. And its wow factor doesn’t end there. Like other Kia vehicles, the K4 has a terrific blend of modern technology and safety features, practicality, and loads of value. And then there’s Kia’s class-leading warranty that includes 10 years/100,000 miles for the powertrain.

Suffice it to say, the Kia K4 is poised to shake up the compact sedan segment.

We’ve logged hundreds of hours driving and evaluating this generation of compact cars, including the Kia K4.

The Kia K4 is new for this model year, a major step forward from the outgoing Forte in terms of space and style.

Most rivals start in the same area as the new K4, like the Toyota Corolla, Hyundai Elantra and Volkswagen Jetta. The Nissan Sentra comes in a little below, while the Honda Civic and Mazda3 are pricier. While even a base Kia K4 LX is a tremendous value and has a strong feature set, we think the EX or GT-Line models are especially attractive while still remaining affordable. The EX trim will get you things like dual 12.3-inch displays, dual-zone climate control, wireless phone charging, 17-inch wheels, and faux leather-wrapped steering wheel. The GT-Line adds a 10-way power driver’s seat, navigation, an AI assistant, and Kia’s excellent Highway Driving Assist systems.

Before buying a new K4 compact sedan, check the Kelley Blue Book Fair Purchase Price to know what you should be paying. Kia Forte resale values are about typical for a compact car, and we wouldn’t be surprised to see the K4 perform a bit better. Remember, recouping more money when you sell a vehicle can mean a bigger down payment and lower monthly payments on your next one.

Most Kia K4 models are powered by a 147-horsepower engine. That doesn’t sound like much, but we were surprised – very pleasantly – that it provides more oomph than expected. We reckon it will be more than fine for most needs of K4 drivers. And there’s always the Sport mode to further liven things up. Bonus points to Kia for putting that right on the steering wheel so you can switch on the fly.

Perhaps the biggest surprise we had when testing the Kia K4 was its transmission. Like so many others in this class, models with the base engine use a continuously variable automatic transmission – a CVT. But it doesn’t feel like a CVT. Only under full-throttle acceleration did we notice much of the rubber-band effect of other CVTs. This one has nice artificial steps that deftly simulate gear changes.

Overall, the K4’s ride quality is taut yet compliant, and we found it a fun partner for running errands and longer highway treks alike.

For those desiring more oomph, the K4 offers that, too. The top-line GT-Line Turbo has (predictably) a turbocharged 1.6-liter 4-cylinder engine that makes a healthy 190 horsepower. It uses an 8-speed automatic transmission in lieu of the CVT.

In our testing of the Kia K4 GT-Line Turbo in and around Austin, we found it an invigorating partner. This powertrain made short work of Texas Hill Country, with power always readily available to tackle elevation changes and passing maneuvers on narrow two-lane roads. The GT-Line trims also appeal to those who like to have a little more fun behind the wheel thanks to their independent rear suspension and quicker steering ratio.

Fuel Economy

The K4 with the base engine earn 34 mpg in combined city/highway driving, according to the EPA. The GT-Line Turbo is predictably thirstier, returning 29 mpg combined. One note of appreciation: The 2025 Kia K4 does not use an engine start/stop system. Though such systems – which cut power at idle – are meant to save a bit of fuel and reduce emissions, some drivers find them aggravating and turn them off anyway every time they start the vehicle. No such issues here.

If we had seen this cabin a couple of years ago, minus the maker’s logo on the steering wheel, we might have surmised that it was a luxury German car. Especially since the K4 offers a Harmon Kardon audio system upgrade — often seen in BMW vehicles — and other premium features like heated and ventilated front seats.

Most of the dashboard — in the higher trims, at least — is taken up by a glass-covered unit that accommodates an instrument cluster, climate control adjustment, and infotainment. The rest of the front section is kept neat, yet still has a decent amount of physical buttons to save the driver delving into menus. We’ve also noted the conventional gear shifter (instead of a push-button system), which gets our approval.

Rear legroom of 38 inches is impressive, about 3 inches more than the Forte. That’s the same as the Hyundai Elantra, and about as good as it gets among compact cars. And even though the Forte had a slightly bigger trunk, the K4’s 14.6 cubic feet is still generous for the class.

We appreciate that two USB-C charging ports come standard in back so rear passengers can keep devices charged. If you want rear air vents, though, you have to step up to the top K4 GT-Line Turbo.

Although the new K4 looks like a coupe, or maybe a hatchback, it’s a sedan. In fact, the rear door handles sit flush, nicely tucked into the C-pillar. The more striking elements, though, are the vertical LED lights front and back, plus the overall design. One thing to be aware of, though, is the design of the rear door. We found the center part juts out when opening, so watch your torso.

The new K4 is almost 3 inches longer than the outgoing Forte, and around an inch longer than the current Honda Civic sedan.

Wireless Apple CarPlay/Android Auto
Cable-free phone integration is standard across the 2025 K4 range. We find this feature wonderfully convenient.

Hey, Kia
This is how to activate the K4’s digital assistant. Things like cabin temperature and audio functions can be controlled with voice commands. It can also provide information on sports scores, owner’s manual information, and much more. It will even listen for follow-up questions.

Dual 12.3-inch displays
It wasn’t so long ago that large luxury cars were at the cutting edge of technology, with twin screens in a single housing — one for driver information and the other an infotainment touchscreen. Now, this setup is offered in higher trims of the 2025 K4 compact sedan. And there’s a smaller screen between these two for adjusting the climate control system.

Blind-Spot View Monitor
Taking blind-spot monitoring to another level, this feature shows real-time video down either side of the car in the driver information display.

Digital Key 2.0
Car keys are so 2023. Owners can share access to their new K4 through a phone app.

Surround-View Monitor
This 360-degree camera system is a boon when trying to negotiate tight spaces.

The base engine in the new K4 is a 2.0-liter 4-cylinder unit making 147 horsepower and 132 lb-ft of torque. It uses a continuously variable transmission. GT-Line Turbo models use a 1.6-liter turbo 4-cylinder making 190 horsepower and 195 lb-ft of torque matched with an 8-speed automatic transmission. All 2025 K4 variants have front-wheel drive.

Class-Leading Warranty

Kia’s warranties are among the best available. Bumper-to-bumper coverage is five years or 60,000 miles, whichever happens first — this includes roadside assistance. Powertrains are covered for 10 years or 100,000 miles.

Safety

Standard safety features include forward collision warning with automatic emergency braking and pedestrian/cyclist detection, lane-keeping assist, and adaptive cruise control.