Compare the2026 BMW M4VS 2025 Mercedes AMG SL

In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the M4 are reminded to check the back seat. The AMG SL doesn’t offer a back seat reminder.

The M4’s standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane and gently nudges the vehicle back towards its lane. A lane departure warning system costs extra on the AMG SL.

Both the M4 and the AMG SL 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, 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 and available around view monitors.

The M4’s corrosion warranty is 7 years longer than the AMG SL’s (12 vs. 5 years).

BMW pays for scheduled maintenance on the M4 for 3 years and 36,000 miles. BMW will pay for oil changes, air filter replacements, cabin filter replacement, brake fluid replacement, inspections, and any other required maintenance. Mercedes doesn’t pay scheduled maintenance for the AMG SL.

J.D. Power and Associates’ 2025 Initial Quality Study of new car owners surveyed provide the statistics that show that BMW vehicles are better in initial quality than Mercedes vehicles. With 14 fewer problems per 100 vehicles, JD Power ranks BMW higher than Mercedes.

J.D. Power and Associates’ 2025 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 above average in long-term dependability. With 13 more problems per 100 vehicles in the first three years of ownership, Mercedes is rated below average.

As tested in Motor Trend the M4 Competition xDrive is faster than the AMG SL 55 4.0 turbo V8 (automatics tested):

On the EPA test cycle the M4 Convertible gets better mileage than the AMG SL running its gasoline engine:

Regardless of its engine, regenerative brakes improve the M4’s fuel efficiency by converting inertia back into energy instead of wasting it. Mercedes only offers a regenerative brake system on the AMG SL 43/63 S E Performance.

The M4 stops shorter than the AMG SL:

For better traction, the M4 has larger front tires than the AMG SL (F:275/40R18 & R:285/35R19 vs. F:255/45R19 & R:285/40R19).

The M4’s standard 275/40R18 front and 285/35R19 rear tires provide better handling because they have a lower 40 series front and 35 series rear profile (height to width ratio) that provides a stiffer sidewall than the AMG SL 43’s standard 45 series front and 40 series rear tires.

For a smoother ride and more stable handling, the M4’s wheelbase is 6.2 inches longer than on the AMG SL (112.5 inches vs. 106.3 inches).

For better maneuverability, the M4’s turning circle is .7 feet tighter than the AMG SL 55/63’s (40 feet vs. 40.7 feet). The M4 xDrive’s turning circle is 1.4 feet tighter than the AMG SL 43’s (41.3 feet vs. 42.7 feet).

The M4’s standard power retractable hardtop allows a seamless transition from an open car, to a completely sealed coupe. The AMG SL doesn’t offer a retractable hardtop.

Because it has more passenger and cargo room, the EPA rates the M4 Convertible a Subcompact car, while the AMG SL is rated a Minicompact.

The M4 Convertible has 8 cubic feet more passenger volume than the AMG SL (84 vs. 76).

The M4 Convertible has a much larger trunk with its top down than the AMG SL with its top down (10.6 vs. 7.5 cubic feet). The M4 Convertible has a much larger trunk with its top up than the AMG SL with its top up (13.6 vs. 8.5 cubic feet).

The M4’s standard rear seats fold to accommodate long and bulky cargo. The AMG SL doesn’t offer folding rear seats.

For greater rear passenger comfort, the M4 has standard rear a/c vents to keep rear occupants more comfortable. The AMG SL doesn’t offer rear vents.

The BMW M4 comes in coupe and convertible bodystyles; the Mercedes AMG SL isn’t available as a coupe.

The BMW 4 Series outsold the Mercedes SL by almost 13 to one during 2024.