Compare the2026 Lexus ISVS 2026 Cadillac CT4

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 Cadillac CT4 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 CT4 doesn’t offer pre-crash pretensioners.

For enhanced safety, the front seat shoulder belts of the Lexus IS are height-adjustable to accommodate a wide variety of driver and passenger heights. A better fit can prevent injuries and the increased comfort also encourages passengers to buckle up. The Cadillac CT4 doesn’t offer height-adjustable seat belts.

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 CT4 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.

Both the IS and CT4 have rear cross-traffic warning, but the IS offers optional Rear Cross-Traffic Braking (automatically applies the brakes) to better prevent a collision when backing near traffic. The CT4’s Rear Cross Traffic Alert doesn’t automatically brake.

Both the IS and the CT4 have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, 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.

A reliable vehicle saves its owner time, money and trouble. Nobody wants to be stranded or have to be without a vehicle while it’s being repaired. Consumer Reports rates the IS’ reliability 20 points higher than the CT4.

J.D. Power and Associates rated the IS first among compact premium cars in their 2025 Initial Quality Study. The CT4 was rated third.

J.D. Power and Associates’ 2025 Initial Quality Study of new car owners surveyed provide the statistics that show that Lexus vehicles are better in initial quality than Cadillac vehicles. J.D. Power ranks Lexus first in initial quality, above the industry average. With 34 more problems per 100 vehicles, Cadillac is ranked 17th, below the industry average.

J.D. Power and Associates’ 2025 survey of the owners of three-year-old vehicles provides the statistics that show that Lexus vehicles are more reliable than Cadillac vehicles. J.D. Power ranks Lexus first in reliability, above the industry average. With 29 more problems per 100 vehicles, Cadillac is ranked fifth.

From surveys of all its subscribers, Consumer Reports’ March 2025 Auto Issue reports that Lexus vehicles are more reliable than Cadillac vehicles. Consumer Reports ranks Lexus second in overall reliability. Cadillac is ranked 21st.

The IS’ 3.5 DOHC V6 produces 74 more horsepower (311 vs. 237) and 22 lbs.-ft. more torque (280 vs. 258) than the CT4’s standard 2.0 turbo 4-cylinder. The IS’ 3.5 DOHC V6 produces 1 more horsepower (311 vs. 310) than the CT4’s optional 2.7 turbo 4-cylinder.

As tested in Car and Driver the Lexus IS is faster than the Cadillac CT4 2.0 turbo 4-cylinder:

The IS has a standard locking fuel door which locks and unlocks with the power locks. The fuel filler door is not lockable on the CT4. A locking fuel door helps prevent fuel theft and vandalism, such as sugar in the tank.

For better stopping power the IS’ front brake rotors are larger than those on the CT4:

The IS stops much shorter than the CT4:

For better traction, the IS has larger standard tires than the CT4 (235/40R19 vs. 225/45R17).

The IS’ standard tires provide better handling because they have a lower 40 series profile (height to width ratio) that provides a stiffer sidewall than the CT4 Luxury’s 45 series tires.

For better ride, handling and brake cooling the IS has standard 19-inch wheels. Smaller 17-inch wheels are standard on the CT4 Luxury.

The IS has a standard space-saver spare tire so you can replace a flat tire and drive to have the flat repaired or replaced. A spare tire isn’t available on the CT4; it requires you to depend on its run-flat tires, which limits mileage and speed before they are repaired. If a run-flat is damaged beyond repair by a road hazard your vehicle will have to be towed. Some tire options on the CT4 don’t have a run-flat feature, either.

For better handling and stability, the track (width between the wheels) on the IS is 1.9 inches wider in the front and 1.5 inches wider in the rear than on the CT4.

The IS 350 F Sport handles at .93 G’s, while the CT4 Premium Luxury AWD pulls only .83 G’s of cornering force in a Motor Trend skidpad test.

The IS 350 F Sport executes Motor Trend’s “Figure Eight” maneuver 1.1 seconds quicker than the CT4 Premium Luxury AWD (25.4 seconds @ .71 average G’s vs. 26.5 seconds @ .67 average G’s).

For better maneuverability, the IS’ turning circle is 2.9 feet tighter than the CT4’s (34.2 feet vs. 37.1 feet). The IS AWD’s turning circle is 2.6 feet tighter than the CT4 AWD’s (35.4 feet vs. 38 feet).

The IS has 2.4 inches more front legroom, 1.3 inches more front hip room, .7 inches more front shoulder room, .4 inches more rear headroom and 1.5 inches more rear hip room than the CT4.

With its sedan body style, valet key, locking rear seatbacks and remote trunk release lockout, the IS offers cargo security. The CT4’s non-lockable folding seat defeats cargo security.

The IS uses gas struts to support the hood for easier service access. The CT4 uses a prop rod to support its heavy hood. It takes two hands to open the hood and set the prop rod, the prop rod gets in the way during maintenance and service, and the prop rod could be knocked out, causing the heavy hood to fall on the person maintaining or servicing the car.

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 CT4 does not have an oil pressure gauge.

The IS’ front and rear power windows all open or close with one touch of the switches, making it more convenient at drive-up windows and toll booths, or when talking with someone outside of the car. The CT4’s rear power window switches have to be held the entire time to close them fully.

If the windows are left open on the IS the driver can close all of them 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 CT4 can only close the windows from inside the vehicle, with the ignition on.

The IS’ 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 CT4’s standard manually variable intermittent wipers have to be constantly adjusted.

In poor weather, headlights can lose their effectiveness as grime builds up on their lenses. This can reduce visibility without the driver realizing. The IS has standard headlight washers to keep headlight output high. The CT4 doesn’t offer headlight washers.

The CT4 Premium Luxury/Sport’s optional cornering lamps activate a lamp on the front corner when the turn signal is activated. The IS’ optional adaptive cornering lights turn the actual headlight unit up to several degrees, depending on steering wheel angle and vehicle speed. This lights a significant distance into corners at any speed.

A power rear sunshade is optional in the IS (except F Sport Design) to help block heat and glare for the rear passengers. The CT4 doesn’t offer a rear sunshade.

Both the Lexus IS and Cadillac CT4 offer exterior mirrors that can be folded to provide convenience. The IS features standard power folding mirrors, which allow for easy, one-touch folding or unfolding at the driver’s discretion. This provides added convenience when maneuvering or parking, as well as when walking past the parked vehicle. In comparison, the CT4’s foldable mirrors are manual, requiring the driver to get out and physically fold them once parked and unfold them before getting in.

The Lexus IS outsold the Cadillac CT4 by almost four to one during 2025.