Compare the2022 BMW M8VS 2021 Mercedes AMG S-Class Cabriolet

The M8 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 AMG S-Class Cabriolet 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 M8 and the AMG S-Class Cabriolet have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, 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, rearview cameras, driver alert monitors, available blind spot warning systems, around view monitors and rear cross-path warning.

The M8’s corrosion warranty is 7 years longer than the AMG S-Class Cabriolet’s (12 vs. 5 years).

BMW pays for scheduled maintenance on the M8 for 3 years and 36,000 miles. BMW will pay for oil changes, lubrication and any other required maintenance. Mercedes doesn’t pay scheduled maintenance for the AMG S-Class Cabriolet.

J.D. Power and Associates’ 2020 Initial Quality Study of new car owners surveyed provide the statistics that show that BMW vehicles are better in initial quality than Mercedes vehicles. J.D. Power ranks BMW 18th in initial quality. With 26 more problems per 100 vehicles, Mercedes is ranked 30th.

J.D. Power and Associates’ 2021 survey of the owners of three-year-old vehicles provides the long-term dependability statistics that show that BMW vehicles are more reliable than Mercedes vehicles. J.D. Power ranks BMW 10th in reliability, above the industry average. With 14 more problems per 100 vehicles, Mercedes is ranked 15th.

From surveys of all its subscribers, Consumer Reports’ January 2021 Auto Issue reports that BMW vehicles are more reliable than Mercedes vehicles. Consumer Reports ranks BMW 8 places higher in reliability than Mercedes.

The M8’s 4.4 turbo V8 produces 14 more horsepower (617 vs. 603) than the AMG S-Class Cabriolet’s 4.0 turbo V8.

As tested in Car and Driver the BMW M8 is faster than the Mercedes AMG S-Class Cabriolet:

Regenerative brakes improve the M8’s fuel efficiency by converting inertia back into energy instead of wasting it. The AMG S-Class Cabriolet doesn’t offer a regenerative braking system.

Both the M8 and the AMG S-Class Cabriolet have a standard automatic start/stop engine feature to stop unnecessary fuel waste and pollution at stop lights and heavy traffic. All M8s have a standard disable switch for the system, so a driver can keep the engine from shutting off when the vehicle stops temporarily.

For better stopping power the M8’s standard brake rotors are larger than those on the AMG S-Class Cabriolet:

For better traction, the M8 has larger front tires than the AMG S-Class Cabriolet (F:275/35R20 & R:285/35R20 vs. F:255/40R20 & R:285/35R20).

The M8’s tires provide better handling because they have a lower 35 series profile (height to width ratio) that provides a stiffer sidewall than the AMG S-Class Cabriolet’s standard 40 series front tires.

The BMW M8 may be more efficient, handle and accelerate better because it weighs about 250 to 500 pounds less than the Mercedes AMG S-Class Cabriolet.

The M8 Coupe/Convertible is 7.1 inches shorter than the AMG S-Class Cabriolet, making the M8 easier to handle, maneuver and park in tight spaces.

The M8 Gran Coupe has standard seating for 5 passengers; the AMG S-Class Cabriolet can only carry 4.

The M8 Convertible has a much larger trunk with its top down than the AMG S-Class Cabriolet with its top down (12.4 vs. 8.8 cubic feet).

The M8’s standard rear seats fold to accommodate long and bulky cargo. The AMG S-Class Cabriolet doesn’t offer folding rear seats, only a ski pass-through.

The M8 has a standard heated steering wheel to take the chill out of steering on extremely cold winter days before the car heater warms up. A heated steering wheel costs extra on the AMG S-Class Cabriolet.