2020 BMW Z4 vs. 2019 Mercedes SL

Detailed Review, Specifications & Comparison

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The Z4 has standard Post-Crash Braking, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The SL 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.

To help make backing safer, the Z4’s optional cross-path warning system uses wide-angle radar in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The SL doesn’t offer a cross-path warning system.

Both the Z4 and the SL have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, rearview cameras, driver alert monitors, available lane departure warning systems, blind spot warning systems and rear parking sensors.


The Z4’s corrosion warranty is 7 years longer than the SL’s (12 vs. 5 years).

BMW pays for scheduled maintenance on the Z4 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 SL.


J.D. Power and Associates’ 2019 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 7th in reliability, above the industry average. With 12 more problems per 100 vehicles, Mercedes is ranked 13th.

From surveys of all its subscribers, Consumer Reports’ December 2018 Auto Issue reports that BMW vehicles are more reliable than Mercedes vehicles. Consumer Reports ranks BMW 9 places higher in reliability than Mercedes.

Fuel Economy and Range

On the EPA test cycle the Z4 gets better fuel mileage than the SL:



sDrive30i 2.0 turbo 4-cyl.

24 city/32 hwy

M40i 3.0 turbo 6-cyl.

24 city/31 hwy


450 3.0 turbo V6

20 city/28 hwy

550 4.7 turbo V8

17 city/25 hwy

AMG 63 5.5 turbo V8

15 city/23 hwy

Regenerative brakes improve the Z4’s fuel efficiency by converting inertia back into energy instead of wasting it. The SL doesn’t offer a regenerative braking system.

Brakes and Stopping

The Z4 stops shorter than the SL:



70 to 0 MPH

146 feet

154 feet

Car and Driver

Suspension and Handling

The Z4 sDrive30i handles at 1.00 G’s, while the AMG SL 63 pulls only .93 G’s of cornering force in a Car and Driver skidpad test.


The BMW Z4 may be more efficient, handle and accelerate better because it weighs about 550 to 650 pounds less than the Mercedes SL.

The Z4 is 11.5 inches shorter than the SL, making the Z4 easier to handle, maneuver and park in tight spaces.

As tested by Car and Driver while at idle, the interior of the Z4 sDrive30i is quieter than the AMG SL 63 (48 vs. 49 dB).

Cargo Capacity

The Z4 has a much larger trunk than the SL with its top down (9.9 vs. 8.5 cubic feet).


The Z4 offers an optional heads-up display that projects speed and other key instrumentation readouts in front of the driver’s line of sight, allowing drivers to view information without diverting their eyes from the road. The SL doesn’t offer a heads-up display.

On extremely cold winter days, the Z4’s optional heated steering wheel provides comfort, allowing the driver to steer safely and comfortably before the car heater warms up. The SL doesn’t offer a heated steering wheel.

© 1991-2018 Advanta-STAR Automotive Research. All rights reserved.

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