Compare the2025 Lexus ISVS 2025 Kia K5

For enhanced safety, the front and rear seat shoulder belts of the Lexus IS have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The Kia K5 doesn’t offer pretensioners for its rear seat belts.

The IS’ optional pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The K5 doesn’t offer pre-crash pretensioners.

The Lexus IS has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags helps prevent the driver and front passenger from sliding under their seatbelts or the main frontal airbags; this keeps them better positioned during a collision for maximum protection. Knee airbags also help keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The K5 doesn’t offer a front passenger side knee airbag.

The IS has a standard Secondary Collision Brake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The K5 doesn’t offer a post collision braking system: in the event of a collision that triggers the airbags, more collisions are possible without the protection of airbags that may have already deployed.

The IS has standard Safety Connect®, which uses a global positioning satellite (GPS) receiver and a cellular system to help track down your vehicle if it’s stolen or send emergency personnel to the scene if any airbags deploy. The K5 doesn’t offer a GPS response system, only a navigation computer with no live response for emergencies, so if you’re involved in an accident and you’re incapacitated help may not come as quickly.

Both the IS and the K5 have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver knee airbags, side-impact head airbags, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, blind spot warning systems, rearview cameras, rear cross-path warning, available all wheel drive and around view monitors.

Instrumented handling tests conducted by the National Highway Traffic Safety Administration and analysis of its dimensions indicate that the IS, with its five-star roll-over rating, is 1.2% less likely to roll over than the K5, which received a four-star rating.

The IS’ corrosion warranty is 1 year and unlimited miles longer than the K5’s (6/unlimited vs. 5/100,000).

J.D. Power and Associates rated the IS first among compact premium cars in their 2024 Initial Quality Study. The K5 isn’t in the top three in its category.

J.D. Power and Associates’ 2024 survey of the owners of three-year-old vehicles provides the statistics that show that Lexus vehicles are more reliable than Kia vehicles. J.D. Power ranks Lexus first in reliability, above the industry average. With 52 more problems per 100 vehicles, Kia is ranked 8th.

From surveys of all its subscribers, Consumer Reports’ January 2024 Auto Issue reports that Lexus vehicles are more reliable than Kia vehicles. Consumer Reports ranks Lexus first in overall reliability. Kia is ranked 10th.

The IS has more powerful engines than the K5:

As tested in Motor Trend the IS 300 AWD 3.5 DOHC V6 is faster than the Kia K5 4 cyl.:

As tested in Motor Trend the IS 500 5.0 DOHC V8 is faster than the Kia K5 (base engine):

The IS has 1.6 gallons more fuel capacity than the K5 (17.4 vs. 15.8 gallons), for longer range between fill-ups.

For better stopping power the IS’ brake rotors are larger than those on the K5:

The IS’ standard front and rear disc brakes are vented to help dissipate heat for shorter stops with less fading. The rear discs on the K5 are solid, not vented.

The IS stops much shorter than the K5:

For better traction, the IS has larger standard tires than the K5 (235/45R18 vs. 205/65R16).

The IS 300’s standard tires provide better handling because they have a lower 45 series profile (height to width ratio) that provides a stiffer sidewall than the K5 LXS’ standard 65 series tires. The IS F Sport’s 265/35R19 rear tires have a lower 35 series profile than the K5 GT’s 40 series tires.

For better ride, handling and brake cooling the IS 300 has standard 18-inch wheels. Smaller 16-inch wheels are standard on the K5 LXS.

The IS offers an available driver-adjustable suspension system. It allows the driver to choose between an extra-supple ride, reducing fatigue on long trips, or a sport setting, which allows maximum control for tricky roads. The K5’s suspension doesn’t offer adjustable shock absorbers.

The IS’ front to rear weight distribution is more even (54% to 46%) than the K5’s (59% to 41%). This gives the IS more stable handling and braking.

The IS 350 F Sport handles at .93 G’s, while the K5 GT-Line AWD pulls only .82 G’s of cornering force in a Motor Trend skidpad test.

The IS 500 Performance executes Motor Trend’s “Figure Eight” maneuver 2.3 seconds quicker than the K5 GT-Line AWD (25.2 seconds @ .74 average G’s vs. 27.5 seconds @ .61 average G’s).

For better maneuverability, the IS’ turning circle is 1.8 feet tighter than the K5’s (34.2 feet vs. 36 feet). The IS AWD’s turning circle is .6 feet tighter than the K5’s (35.4 feet vs. 36 feet).

The IS is 7.7 inches shorter than the K5, making the IS easier to handle, maneuver and park in tight spaces.

With its sedan body style, valet key, locking rear seatbacks and remote trunk release lockout, the IS offers cargo security. The K5’s non-lockable remote release defeats cargo security.

A standard locking glovebox (which can’t be accessed with the valet key) keeps your small valuables safer in the IS. The K5 doesn’t offer locking storage for small valuables.

The engine in the IS is mounted longitudinally (North-South), instead of sideways, as in the K5. This makes it easier to service and maintain, because the accessory belts are in front.

J.D. Power and Associates surveys of service recipients show that Lexus service is better than Kia. J.D. Power ranks Lexus first in service department satisfaction. With a 59% lower rating, Kia is ranked 24th.

Unlike the driver-only memory seat and mirrors in the K5 EX/GT1, the IS offers an optional driver and passenger memory, so that when drivers switch, the memory setting adjusts the driver’s seat, steering wheel position and outside mirror angle and the front passenger seat also adjusts to the new passenger’s preset preferences.

The IS’ instruments include an oil pressure gauge and a temperature gauge - which could save your engine! Often ‘idiot lights’ don’t warn you until damage has been done. The K5 does not have an oil pressure gauge.

The IS’ front and rear power windows all open or close fully with one touch of the switches, making it more convenient at drive-up windows and toll booths, or when talking with someone outside the car. The K5’s standard passenger windows don’t open or close automatically.

If the windows are left open on the IS the driver can close them all at the outside door handle. On a hot day the driver can lower the windows at the outside door handle or from a distance using the keyless remote. (This window function must be activated by your Lexus service department.) The driver of the K5 can only close the windows from inside the vehicle, with the ignition on.

The IS’ optional wipers adjust their speed and turn on and off automatically according to the amount of rainfall on the windshield. The K5’s manually variable intermittent wipers have to be constantly adjusted.

To help drivers see further while navigating curves, the IS offers optional adaptive headlights to illuminate around corners automatically by reading vehicle speed and steering wheel angle. The K5 doesn’t offer cornering lights.

A power rear sunshade is optional in the IS to help block heat and glare for the rear passengers. The K5 doesn’t offer a rear sunshade.

The IS’ standard rear and side view mirrors have an automatic dimming feature. These mirrors can be set to automatically darken quickly when headlights shine on them, keeping following vehicles from blinding or distracting the driver. The K5 offers an automatic rear view mirror, but its side mirrors don’t dim.

Both the IS and the K5 offer rear vents. For greater rear passenger comfort, the IS has standard rear air conditioning vents to keep rear occupants cool in summer or warm in winter. The K5 doesn’t offer rear air conditioning vents, only heat vents.

Consumer Reports® recommends the Lexus IS, based on reliability, safety and performance.