2025 Kia K4 vs. K5: What’s the Difference Between These Two Eye-Catching Sedans?
Both Kia sedans share wild styling and appealing features, but each has advantages worth considering.
In 2021, Kia replaced the dowdy Optima with the K5, a stylish, high-tech, and all-around more inspiring sedan than its predecessor. A 2025 refresh only enhances its best attributes. Now Kia attempts to repeat this success in the compact car space as it replaces the aged Forte with the new K4, which will be offered in both sedan and hatchback variants. How do these two striking Kia cars compare when it comes to performance, interior space, tech, and price? That’s what we’ll explore in this 2025 Kia K4 versus Kia K5 specs comparison.
2025 Kia K4 vs. K5: Exterior Measurements
Simply put, the K4 is smaller than the K5. The K4 is a compact sedan (like the Honda Civic) and the K5 is a midsize sedan (like the Honda Accord). The K4 measures 185.4 inches in overall length, while the K5 is 193.1 inches long. Width is close between the two, measuring 72.8 inches for the K4 and 73.2 inches for the K5.
In becoming the K4, size also increases compared to the Forte, which measured 182.7 inches long and 70.9 inches wide.
2025 Kia K4 vs. K5: Passenger and Cargo Space
Kia claims best-in-class second-row headroom and legroom for the K4. Those measurements are 37.3 inches and 38.0 inches, respectively. In the K5’s back seat, headroom is 37.8 inches, but legroom is 35.2 inches—that’s right, the K4 has more rear legroom than the K5. But in the front seats, the K5 has 40.2 inches of headroom and a whopping 46.1 inches of legroom, figures the K4 likely won’t match or surpass.
Trunk space in the K4 sedan comes in at 14.6 cubic feet, pretty good for a compact car. The K5’s cargo hold is slightly larger, presenting 15.6 cubic feet of space. However, Kia will offer the K4 as a five-door hatchback, which should have more cargo capacity than either sedan model. Details on the K4 hatchback have yet to be released.
Strangely, the K4 isn’t as spacious as the Forte in some areas. Although the K4 sedan has considerably more rear legroom than the Forte, it has less rear headroom and trunk space. The Forte had 35.7 inches of rear legroom, 37.5 inches of rear headroom, and 15.3 cubic feet of cargo capacity.
2025 Kia K4 vs. K5: Engines and MPGs
The K4’s engines are essentially identical to those used in the Forte. As standard, the K4 is equipped with a 2.0-liter I-4 that produces 147 hp and 132 lb-ft of torque, which goes to the front wheels via a CVT automatic; AWD is not available. Given that’s the same setup used in the Forte, expect a 0–60-mph time of around 8.0 seconds and fuel economy of 30/40 mpg city/highway.
For 2025, the K5 received a new standard engine: a 2.5-liter I-4 making 191 hp and 181 lb-ft of torque, joined to an eight-speed automatic transmission. The K5 comes standard with FWD and offers optional AWD. Acceleration from 0 to 60 mph should take slightly less than 8.0 seconds like in previous model years. Fuel economy for the 2025 K5 comes in at 23-26/33-37 mpg, depending on configuration.
Both the K4 and K5 offer a turbocharged engine as an upgrade. In the K4 GT-Line Turbo, it’s a 1.6-liter I-4 that makes 190 hp and 195 lb-ft of torque. This engine was used in the Forte GT, but in the K4 it makes less power, down from 201 hp. That’s likely a mechanical limitation of the mandatory eight-speed automatic transmission; a seven-speed dual-clutch or six-speed manual was offered in the Forte GT. Meanwhile, the K5 GT packs a 2.5-liter turbo I-4 pushing 290 hp and 310 lb-ft of torque to the front wheels via an eight-speed dual-clutch automatic. In MotorTrend testing, the K5 GT accelerated from 0 to 60 mph in 5.4 seconds. Fuel economy for the K5 GT comes in at 23/33 mpg; the Forte GT-Line Turbo will likely be more efficient.
2025 Kia K4 vs. K5: Tech Features
In higher-end trim levels, both the K4 and K5 get a 5.0-inch climate control panel positioned between a 12.3-inch digital gauge cluster and 12.3-inch infotainment touchscreen. That infotainment runs Kia’s new ccNC (Connected Car Navigation Cockpit) user interface, which made its debut in the EV9 electric SUV. Not only is ccNC more user friendly and responsive than Kia’s outgoing system, but it has over-the-air update capability and an AI-enhanced digital assistant.
Entry-level versions of the K5 get analog gauges with a 4.2-inch digital display between them, a setup that could be shared with basic K4 models. Regardless, all versions have wireless Apple CarPlay and Android Auto connectivity. Both vehicles offer USB-C charge ports and a wireless charging pad. Premium tech features for the K4 and K5 include phone-as-key functionality, a 360-degree camera, and premium speakers.
2025 Kia K4 vs. K5: Safety Features
Kia doesn’t skimp on equipping the K4 and K5 with useful driver assist and active safety tech—it needs to compete with Honda and Toyota, after all. Both 2025 Kia sedans have front automatic emergency braking with cyclist and pedestrian detection, intersection collision avoidance, road sign recognition, lane keep assist, and adaptive cruise control.
Optional or included depending on trim are features such as rear cross-traffic alert, enhanced adaptive cruise control, and nifty camera-based blind-spot monitoring that shows a video image of what’s behind the vehicle in the digital gauge display.
2025 Kia K4 vs. K5: Price
Available for just more than $21,000 in entry-level spec, the outgoing Forte was one of the cheapest new cars on sale. It’s likely the K4’s starting price will be higher—that’s just how things go. But hopefully it will remain relatively affordable, potentially at about $23,000 for the sedan. Expect the K4 hatchback to command a slight price premium, and high-end models of either K4 body style to top out at around $30,000.
Pricing for the 2024 Kia K5 started at slightly less than $27,000 for the LXS trim and peaked at just above $33,000 for the sporty GT model. The 2025 K5 could become more expensive, but likely not by a great amount. The refreshed K5 is expected in spring 2024, while the K4 will arrive in the second half of the year.
2025 Kia K4 vs. K5: Key Differences
Kia K4
- Compact sedan and hatchback
- More rear legroom than K5
- Should be less expensive than K5
- Likely more efficient
Kia K5
- Midsize sedan
- More cargo space than K4 sedan
- More powerful engines
- AWD available
Alex's earliest memory is of a teal 1993 Ford Aspire, the car that sparked his automotive obsession. He's never driven that tiny hatchback—at six feet, 10 inches tall, he likely wouldn't fit—but has assessed hundreds of other vehicles, sharing his insights on MotorTrend as a writer and video host.
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