Compare the2022 Porsche Cayenne CoupeVS 2021 Mercedes AMG GLB

The Porsche Cayenne Coupe 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 AMG GLB doesn’t offer a front passenger side knee airbag.

The Cayenne Coupe has a standard Multi-collision Brake System, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The AMG GLB 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.

A passive infrared night vision system optional on the Cayenne Coupe helps the driver to more easily detect people, animals or other objects in front of the vehicle at night. Using an infrared camera to detect heat, the system then displays the image on a monitor in the dashboard. The AMG GLB doesn’t offer a night vision system.

To help make backing out of a parking space safer, the Cayenne Coupe’s optional rear cross-path warning system uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The AMG GLB doesn’t offer a cross-path warning system.

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

The Porsche Cayenne Coupe weighs 794 to 1804 pounds more than the Mercedes AMG GLB. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.

The Cayenne Coupe’s corrosion warranty is 7 years longer than the AMG GLB’s (12 vs. 5 years).

J.D. Power and Associates rated the Cayenne Coupe third among upper midsize premium suvs in their 2021 Initial Quality Study. The AMG GLB isn’t in the top three in its category.

J.D. Power and Associates’ 2021 Initial Quality Study of new car owners surveyed provide the statistics that show that Porsche vehicles are better in initial quality than Mercedes vehicles. J.D. Power ranks Porsche 15th in initial quality. With 30 more problems per 100 vehicles, Mercedes is ranked 25th.

J.D. Power and Associates’ 2021 survey of the owners of three-year-old vehicles provides the long-term dependability statistics that show that Porsche vehicles are more reliable than Mercedes vehicles. J.D. Power ranks Porsche second in reliability, above the industry average. With 36 more problems per 100 vehicles, Mercedes is ranked 15th.

From surveys of all its subscribers, Consumer Reports’ January 2021 Auto Issue reports that Porsche vehicles are more reliable than Mercedes vehicles. Consumer Reports ranks Porsche 11 places higher in reliability than Mercedes.

The Cayenne Coupe’s standard 3.0 turbo V6 produces 33 more horsepower (335 vs. 302) and 37 lbs.-ft. more torque (332 vs. 295) than the AMG GLB’s 2.0 turbo 4-cylinder. The Cayenne S Coupe’s standard 2.9 turbo V6 produces 132 more horsepower (434 vs. 302) and 110 lbs.-ft. more torque (405 vs. 295) than the AMG GLB’s 2.0 turbo 4-cylinder. The Cayenne GTS Coupe’s standard 4.0 turbo V8 produces 151 more horsepower (453 vs. 302) and 162 lbs.-ft. more torque (457 vs. 295) than the AMG GLB’s 2.0 turbo 4-cylinder. The Cayenne E-Hybrid Coupe’s standard 3.0 turbo V6 hybrid produces 153 more horsepower (455 vs. 302) and 221 lbs.-ft. more torque (516 vs. 295) than the AMG GLB’s 2.0 turbo 4-cylinder. The Cayenne Turbo S E-Hybrid Coupe’s standard 4.0 turbo V8 hybrid produces 368 more horsepower (670 vs. 302) and 368 lbs.-ft. more torque (663 vs. 295) than the AMG GLB’s 2.0 turbo 4-cylinder.

On the EPA test cycle the Cayenne Coupe running on electricity gets better mileage than the AMG GLB:

The Cayenne E-Hybrid Coupe can drive on battery power alone for up to 17 miles. The AMG GLB must run its internal combustion engine to move.

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

The Cayenne Coupe E-Hybrid’s standard fuel tank has 3.9 gallons more fuel capacity than the AMG GLB (19.8 vs. 15.9 gallons), for longer range between fill-ups. The Cayenne Coupe’s standard fuel tank has 7.8 gallons more fuel capacity than the AMG GLB (23.7 vs. 15.9 gallons).

For better stopping power the Cayenne Coupe’s brake rotors are larger than those on the AMG GLB:

The Cayenne Coupe offers optional heat-treated ceramic brake rotors, which last ten to twenty times as long as conventional cast iron rotors, don’t rust, don’t fade during repeated high speed braking, and their lighter weight contribute to better braking, handling and acceleration. The AMG GLB doesn’t offer ceramic brake rotors.

The Cayenne Coupe Turbo has standard air brakes, which adjust the spoiler automatically during high-speed braking in order to shorten stopping distances. The AMG GLB doesn’t offer air brakes.

For better traction, the Cayenne Coupe has larger standard tires than the AMG GLB (F:275/45R20 & R:305/40R20 vs. 235/50R19). The Cayenne Coupe’s optional tires are larger than the largest tires available on the AMG GLB (F:285/40R21 & R:315/35R21 vs. 255/40R20).

The Cayenne Coupe’s standard 275/45R20 front and 305/40R20 rear tires provide better handling because they have a lower 45 series front and 40 series rear profile (height to width ratio) that provides a stiffer sidewall than the AMG GLB’s standard 50 series tires. The Cayenne Coupe’s optional 315/30R22 rear tires have a lower 30 series profile than the AMG GLB’s optional 35 series tires.

For better ride, handling and brake cooling the Cayenne Coupe has standard 20-inch wheels. Smaller 19-inch wheels are standard on the AMG GLB. The Cayenne Coupe’s optional 22-inch wheels are larger than the 21-inch wheels optional on the AMG GLB.

The Cayenne Coupe has a standard space-saver spare (not available on E-Hybrid) so you can replace a flat tire and drive to have the flat repaired or replaced. A spare tire isn’t available on the AMG GLB; 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 AMG GLB don’t have a run-flat feature, either.

The Cayenne Coupe has standard front and rear gas-charged shocks for better control over choppy roads. The AMG GLB’s suspension doesn’t offer gas-charged shocks.

The Cayenne Coupe offers active sway bars, which help keep it flat and controlled during cornering, but disconnect at lower speeds to smooth the ride and offer greater off-road suspension articulation. This helps keep the tires glued to the road on-road and off. The AMG GLB doesn’t offer an active sway bar system.

The Cayenne Coupe offers an available adjustable active suspension system, which counteracts cornering forces actively, limiting body roll and improving handling and stability. Mercedes doesn’t offer an active suspension on the AMG GLB.

The Cayenne Coupe has a standard automatic load leveling suspension to keep ride height level with a heavy load or when towing. The AMG GLB doesn’t offer a load leveling suspension.

For a smoother ride and more stable handling, the Cayenne Coupe’s wheelbase is 2.6 inches longer than on the AMG GLB (114 inches vs. 111.4 inches).

For better handling and stability, the average track (width between the wheels) on the Cayenne Coupe is 2.5 inches wider in the front and 3.4 inches wider in the rear than the track on the AMG GLB.

For better maneuverability, the Cayenne Coupe w/Rear Wheel Steering’s turning circle is 5.9 feet tighter than the AMG GLB’s (35.1 feet vs. 41 feet). The Cayenne Coupe’s turning circle is 1.2 feet tighter than the AMG GLB’s (39.8 feet vs. 41 feet).

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

The Cayenne Coupe has 3.2 inches more front shoulder room, 1.9 inches more rear legroom and 1.6 inches more rear shoulder room than the AMG GLB.

The Cayenne Coupe has a much larger cargo volume than the AMG GLB with its rear seat up (22 vs. 5.1 cubic feet).

The Cayenne Coupe has a 7700 lbs. towing capacity. The AMG GLB has no towing capacity.

A trailer sway program is standard on the Cayenne Coupe uses the Porsche Stability Management sensors to detect trailer sway, then uses individual brakes to counteract any swaying and help keep the tow vehicle and trailer steady. The AMG GLB doesn’t offer electronic trailer sway control.

The engine in the Cayenne Coupe is mounted longitudinally (North-South), instead of sideways, as in the AMG GLB. 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 Porsche service is better than Mercedes. J.D. Power ranks Porsche first in service department satisfaction. With a 32% lower rating, Mercedes is ranked 6th.

The Cayenne Coupe’s 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 AMG GLB does not have an oil pressure gauge.

In poor weather, headlights can lose their effectiveness as grime builds up on their lenses. This can reduce visibility without the driver realizing. The Cayenne Coupe offers available headlight washers to keep headlight output high. The AMG GLB doesn’t offer headlight washers.

Manual rear side window sunshades are available in the Cayenne Coupe to help block heat and glare for the rear passengers. The AMG GLB doesn’t offer rear side window sunshades.

Both the Cayenne Coupe and the AMG GLB offer optional heated front seats. The Cayenne Coupe also offers optional heated rear seats to keep those passengers extremely comfortable in the winter. Heated second row seats aren’t available in the AMG GLB.

The Cayenne Coupe’s optional Active Park Assist can parallel park or back into a parking spot by itself, starting, stopping and changing direction automatically. Remote Park Assist will park and retrieve your car remotely: press a button and watch it park itself. This is ideal for tight locations. The AMG GLB’s automatic parking system does not offer parking by remote control.

Consumer Reports® recommends the Porsche Cayenne Coupe, based on reliability, safety and performance.