The CLA's 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 Mercedes CLA has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags help 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 CLA's standard pretensioning seatbelts also sense rear collisions and remove slack from the seatbelts to help protect the occupants from whiplash and other injuries. The K5 doesn't offer a whiplash protection system.

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

The CLA's 5 year corrosion warranty has no mileage limitations, but the corrosion warranty on the K5 runs out after 100,000 miles.

The CLA's 2.0 turbo 4-cylinder hybrid produces 30 more horsepower (221 vs. 191) and 77 lbs.-ft. more torque (258 vs. 181) than the K5's standard 2.5 DOHC 4-cylinder.

As tested in Motor Trend the Mercedes CLA is faster than the Kia K5 4 cyl.:

On the EPA test cycle the CLA gets better mileage than the K5:

Regenerative brakes improve the CLA's fuel efficiency by converting inertia back into energy instead of wasting it. The K5 doesn't offer a regenerative braking system.

Both the CLA and the K5 LX have a standard automatic start/stop engine feature to stop unnecessary fuel waste and pollution at stoplights and heavy traffic. All CLAs have a standard disable switch for the system, so a driver can keep the engine from shutting off when the vehicle stops temporarily.

In its Green Vehicle Guide, the U.S. Environmental Protection Agency (EPA) rates the Mercedes CLA higher (7 out of 10) than the Kia K5 (4 to 6). This means the CLA produces up to 13.2 pounds less smog-producing pollutants than the K5 every 15,000 miles.

For better stopping power the CLA's standard brake rotors are larger than those on the K5:

In an emergency stopping situation, many drivers don't press the brakes with enough force to stop the vehicle in the shortest distance. The CLA has standard Brake Assist to detect emergency braking situations (by how hard and how quickly the brake pedal is pressed) and then automatically apply maximum braking immediately in order to help prevent a collision. The K5 doesn't offer a brake assist feature.

The CLA stops much shorter than the K5:

For better traction, the CLA has larger tires than the K5 (225/45R18 vs. 205/65R16).

The CLA'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.

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

Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires available on the CLA can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The K5 doesn't offer run-flat tires.

The CLA offers an optional 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 CLA's drift compensation steering can automatically compensate for road conditions which would cause the vehicle to drift from side to side, helping the driver to keep the vehicle straight more easily. The K5 doesn't offer drift compensation steering.

The CLA 250 4MATIC handles at .87 G's, while the K5 GT-Line AWD pulls only .82 G's of cornering force in a Motor Trend skidpad test.

The CLA 250 4MATIC executes Motor Trend's “Figure Eight” maneuver 1 seconds quicker than the K5 GT-Line AWD (26.5 seconds @ .65 average G's vs. 27.5 seconds @ .61 average G's).

The CLA is 8.5 inches shorter than the K5, making the CLA easier to handle, maneuver and park in tight spaces.

To allow full utilization of available cargo room, the CLA's trunk lid uses concealed beam hinges that don't intrude into the trunk. Its intrusive beam hinge reduces the K5's useful trunk space.

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

Unlike the driver-only memory seat and mirrors optional at extra cost in the K5 (except LXS/GT-Line), the CLA has standard driver and passenger memory, so that when drivers switch, the memory setting adjusts the driver's seat and outside mirror angle and the front passenger seat also adjusts to the new passenger's preset preferences.

The CLA's standard easy entry and exit feature glides the driver's seat back, making it easier for the driver to get in and out. An easy entry system costs extra on the K5, and is not available on all models.

The CLA offers an optional heads-up display that projects speed and navigation instruction readouts in front of the driver's line of sight, allowing drivers to view information without diverting their eyes from the road. The K5 doesn't offer a heads-up display.

The CLA's 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. The K5's optional .

If the windows are left open on the CLA the driver can close all of them at the outside door handle or from a distance using the remote. On a hot day the driver can lower the windows from a distance using the keyless remote. The driver of the K5 can only close the windows from inside the vehicle, with the ignition on.

The CLA's rain-sensitive wipers adjust their speed and turn on and off automatically based on the amount of rainfall on the windshield. This allows the driver to concentrate on driving without constantly adjusting the wipers. The K5's manually variable intermittent wipers have to be constantly adjusted.

Heated windshield washer nozzles are optional on the CLA to prevent washer fluid and nozzles from freezing and help continue to keep the windshield clear in sub-freezing temperatures. The K5 doesn't offer heated windshield washer nozzles.

To help drivers avoid possible obstacles, the CLA offers optional cornering lights to illuminate around corners when the turn signals are activated. The K5 doesn't offer cornering lights. The CLA also offers optional adaptive headlights to illuminate around corners automatically by reading vehicle speed and steering wheel angle.

The CLA's 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.

The Mercedes CLA has power folding mirrors that offer unparalleled convenience while maneuvering in tight places or parked. With the mirrors folded it's easier to walk past and help prevent parking damage. The mirrors can be quickly unfolded when the driver is ready to leave. Power folding mirrors costs extra on the K5 and aren't offered on the LXS/GT-Line.

Both the CLA and the K5 offer rear vents. For greater rear passenger comfort, the CLA 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.

The CLA's optional Active Parking Assist can parallel park or back into a parking spot by itself, starting, stopping and changing direction automatically. The K5 doesn't offer an automated parking system.