Compare the2024 BMW X4VS 2024 Acura RDX

The X4’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The RDX doesn’t offer pre-crash pretensioners.

The X4 has standard Active Head Restraints, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the Active Head Restraints system moves the headrests forward to prevent neck and spine injuries. The RDX doesn’t offer a whiplash protection system.

The X4 has a standard PostCrash iBrake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The RDX 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.

Over 200 people are killed each year when backed over by motor vehicles. The X4 offers an optional Active Park Distance Control that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The RDX doesn’t offer backup collision prevention brakes.

The X4’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The RDX doesn’t offer a driver alert monitor.

Both the X4 and the RDX have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, plastic fuel tanks, four-wheel antilock brakes, all wheel drive, 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 and available around view monitors.

The X4’s corrosion warranty is 7 years longer than the RDX’s (12 vs. 5 years).

BMW pays for scheduled maintenance on the X4 for 1 year and 12000 miles longer than Acura pays for maintenance for the RDX (3/36,000 vs. 2/24,000).

There are over 28 percent more BMW dealers than there are Acura dealers, which makes it easier should you ever need service under the X4’s warranty.

J.D. Power and Associates rated the X4 second among compact premium suvs in their 2023 Initial Quality Study. The RDX isn’t in the top three in its category.

J.D. Power and Associates’ 2023 Initial Quality Study of new car owners surveyed provide the statistics that show that BMW vehicles are better in initial quality than Acura vehicles. With 15 fewer problems per 100 vehicles, JD Power ranks BMW higher than Acura.

J.D. Power and Associates’ 2022 survey of the owners of three-year-old vehicles provides the long-term dependability statistics that show that BMW vehicles are more reliable than Acura vehicles. J.D. Power ranks BMW above average in long-term dependability. With 5 more problems per 100 vehicles in the first three years of ownership, Acura is rated below average.

The X4 M40i’s standard 3.0 turbo 6-cylinder hybrid produces 110 more horsepower (382 vs. 272) and 89 lbs.-ft. more torque (369 vs. 280) than the RDX’s 2.0 turbo 4-cylinder.

On the EPA test cycle the X4 gets better mileage than the RDX:

Regenerative brakes improve the X4’s fuel efficiency by converting inertia back into energy instead of wasting it. The RDX doesn’t offer a regenerative braking system.

For better stopping power the X4’s brake rotors are larger than those on the RDX:

The X4’s standard front and rear disc brakes are vented to help dissipate heat for shorter stops with less fading. The rear discs on the RDX are solid, not vented.

The X4 stops much shorter than the RDX:

For better traction, the X4 has larger standard tires than the RDX (245/50R19 vs. 235/55R19).

The X4’s standard tires provide better handling because they have a lower 50 series profile (height to width ratio) that provides a stiffer sidewall than the RDX’s standard 55 series tires. The X4’s optional 245/40R21 front and 275/35R21 rear tires have a lower 40 series front and 35 series rear profile than the RDX A-Spec’s 45 series tires.

For better ride, handling and brake cooling the X4 offers optional 21-inch wheels. The RDX’s largest wheels are only 20-inches.

Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires standard on the X4 can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The RDX doesn’t offer run-flat tires.

For a smoother ride and more stable handling, the X4’s wheelbase is 4.5 inches longer than on the RDX (112.8 inches vs. 108.3 inches).

The X4’s front to rear weight distribution is more even (49.2% to 50.8%) than the RDX’s (57% to 43%). This gives the X4 more stable handling and braking.

The X4 M40i handles at .89 G’s, while the RDX pulls only .81 G’s of cornering force in a Motor Trend skidpad test.

The X4 M40i executes Motor Trend’s “Figure Eight” maneuver 2.1 seconds quicker than the RDX (25.6 seconds @ .73 average G’s vs. 27.7 seconds @ .62 average G’s).

The front grille of the X4 uses electronically controlled shutters to close off airflow and reduce drag when less engine cooling is needed. This helps improve highway fuel economy. The RDX doesn’t offer active grille shutters.

For enhanced passenger comfort on long trips the X4’s rear seats recline. The RDX’s rear seats don’t recline.

The engine in the X4 is mounted longitudinally (North-South), instead of sideways, as in the RDX. This makes it easier to service and maintain, because the accessory belts are in front.

The X4’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 RDX’s standard intermittent wipers change speed with vehicle speed, but can’t turn on and off or change speed based on changing rainfall.

To help drivers avoid possible obstacles, the X4 has standard cornering lights to illuminate around corners when the turn signals are activated. The RDX doesn’t offer cornering lights. The X4 also has standard adaptive headlights to illuminate around corners automatically by reading vehicle speed and steering wheel angle.

The X4’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 RDX has an automatic rear view mirror, but its side mirrors don’t dim.

The X4’s optional Parking Assistant Plus can parallel park or back into a parking spot by itself, starting, stopping and changing direction automatically. The RDX doesn’t offer an automated parking system.

J.D. Power and Associates rated the X4 first among compact premium suvs in owner reported satisfaction. This includes how well the vehicle performs and satisfies its owner’s expectations. The RDX isn’t in the top three.