Kia K4 2025 review: GT-Line sedan

The new K4 sedan is offered in four grades - the base-model S which has an optional 'Safety Pack' available, the mid-spec Sport and Sport+ grades and the flagship GT-Line, which is the model on test for this review.

The GT-Line is sharply priced at $42,990, before on road costs. This positions it in the middle of its small sedan rivals, the Hyundai i30 N Line Premium ($41,500 MSRP) and the Mazda3 Astina ($43,310 MSRP).

What the K4 GT-Line has going for it over its peers is a standard specification list that features some heavy-hitting technology.

2025 Kia K4 GT-Line (image: Glen Sullivan)

This includes dual 12.3-inch displays, a 5.0-inch climate display, built-in satellite navigation with 10-years' of map updates, wireless/wired Apple CarPlay and Android Auto and dual-zone climate control.

Charging is taken care of by two USB-C ports for each row but the front row also enjoys a 12-volt socket and fast wireless charging pad in the dedicated phone cradle.

There's also an eight-speaker Harman Kardon sound system, over-the-air updates, digital radio, AM/FM radio, Bluetooth connectivity, and a 'Sounds of Nature' soundscape for added ambience.

2025 Kia K4 GT-Line (image: Glen Sullivan)

The Kia Connect app is also included and this allows user access to the emergency call functionality (e-Call), remote control functions for the vehicle, as well as vehicle status monitoring.

Premium equipment includes a tilt and slide sunroof with electric sunshade, two-tone synthetic leather upholstery, heated and ventilated front seats, an electric drivers seat (with two-position memory function and adjustable lumbar support) and a heated steering wheel.

For a small sedan, it comes packed with features!

The K4 feels big for the class, especially compared to its nearest rivals and that translates to a cabin that feels adult-friendly in both rows. An impressive feat for a small sedan.

Access is the only time you will have moments of 'I should have opted for an SUV'. That's because you will get in your daily squats sliding in and out of the K4 due to its 140mm ground clearance.

The rear doors also feature a wide wing that juts out from the door handle and it catches your hip almost every time you go to close the door.

2025 Kia K4 GT-Line (image: Glen Sullivan)

The wide front seats offer lots of comfort with thick padding and long under-thigh-support. The driver's side is powered with adjustable lumbar support but the passenger seat only offers manual adjustments, which is surprising for a top-grade model. However, both front seats enjoy heat and ventilation functions.

The back bench seat offers similar comfort to the front with seat padding and length but it's not terribly wide and two adults (or child car seats) will fit best.

Amenities and storage is decent for the class with each row enjoying four drink holders and two USB-C ports. Front rowers also get a wireless charging pad and 12-volt socket.

In the front there is a large glove box that fits more than just an owner's manual, a mid-size middle console and a centre console that features retractable cupholders to open up the space if you need to. A dedicated phone cradle with small spaces on each side rounds up individual storage for the front.

In the rear there are two map pockets, a small item cubby next to the USB-C ports and a pair of directional air vents, reading lights and a fold-down armrest.

The boot space is massive for the class at 508L (that's nearing mid-size SUV territory) but the aperture is narrow and I couldn't fit my big booster seat through the opening.

2025 Kia K4 GT-Line (image: Glen Sullivan)

The boot is quite deep as well and you may find yourself climbing into it to retrieve items that roll into the back.

The rear bench seat has a 60/40 split which can help with storage and there is a temporary spare tyre underneath the floor.

While you don't get a powered tailgate in this model, the lid isn't heavy to operate and has a proximity opening function that keeps it practical when you have your hands full.

2025 Kia K4 GT-Line (image: Glen Sullivan)

This just means when you approach and stay near the boot with the key fob on your person the boot lid will pop open for you.

The 12.3-inch touchscreen multimedia system looks great with crisp graphics and a responsive touchscreen. The menus are in an easy-to-understand layout which you'll get accustomed to in no time. The 5.0-inch climate display sits to the right of this system and it's nice to have it on display all the time.

The 12.3-inch digital instrument cluster isn't all that customisable but it's easy to read with large text and a small menu screen that shows nav directions, trip info or a compass.

2025 Kia K4 GT-Line (image: Glen Sullivan)

The built-in satellite navigation system is easy to get going and to cancel a route guidance, it's a one button affair which is great for when you're on the go.

The system features wired and wireless Apple CarPlay and Android Auto. The CarPlay is simple to connect to and retained a steady connection this week with feedback from my callers that my voice was clear on calls.

The flagship grade is front-wheel drive and has a 1.6-litre four-cylinder, turbo-petrol engine that produces up to 142kW of power and 265Nm of torque giving this a more powerful presence than its non-turbo siblings (which only produce up to 112kW/192Nm).

However, while the power is adequate for the GT-Line there are times when the engine sounds like it's working a bit too hard.

The eight-speed torque-converter automatic transmission can also become flustered as it moves through the lower gears, especially when you’re accelerating quickly.

On the whole, the power delivery and outputs are more than enough for a city environment and the odd road trip.

With an official combined (urban/extra-urban) cycle fuel usage figure of 6.7L/100km and a fuel tank size of 47L, this model has a theoretical driving range of 701km. That does sit around 80 kays less than some of its rivals but it’s still sufficient for those wanting to do the odd road trip!

My on-test fuel usage has popped out at 9.2L/100km, which is based on figures achieved at the pump (32.05L) and my km travelled (348km).

I’ve done mostly urban trips this week with one longer open-road drive and overall I’m not too surprised by that figure because I’ve been pushing it hard but it could be better.

The K4 is a simple gal because Kia recommends a minimum 91 RON unleaded petrol to be used for all models.

2025 Kia K4 GT-Line (image: Glen Sullivan)

The Kia K4 has just been launched and hasn’t been tested by ANCAP yet, so is unrated but Kia is hustling to get it tested so it can join in on their strong five-star performance record. The K4 has seven airbags, including a front centre airbag.

The K4 GT-Line has all of the bells and whistles when it comes to safety equipment and includes the big-ticket items like blind-spot monitoring and collision avoidance, intelligent seatbelt warning (all seats), rear cross-traffic alert, front cross-traffic alert, lane keeping aid, lane departure alert, leading vehicle alert, emergency call functionality, side exit warning, rear occupant alert, traffic sign recognition, driver monitoring and alert, LED DRLs, dusk-sensing LED headlights, front/rear parking sensors and a reversing camera with dynamic guidelines.

2025 Kia K4 GT-Line (image: Glen Sullivan)

The K4 GT-Line has AEB with forward collision warning, car, pedestrian, cyclist, and junction crossing detection.

The rear seat has two ISOFIX child seat mounts on the outboard positions and three top tether anchor points but two seats will fit best.

Kia has become well-known for having annoying sound alerts in their cars and while the K4 has them too - you can easily disable the most annoying one, the traffic sign recognition, by holding the steering wheel volume button in for a few seconds.