BMW 4 Series Convertible vs Mercedes-Benz Mercedes-AMG SL Roadster

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4 Series Convertible compared with Mercedes-AMG SL Roadster

	BMW4 Series Convertible	Mercedes-BenzMercedes-AMG SL Roadster
Overview
Released
Released	March 2021	2022
Performance
Powertrain
Powertrain	Petrol, Mild hybrid	Mild hybrid, Petrol, Plug-in hybrid
Power
Power	181–386 bhp	416–805 bhp (better)
0–62 mph
0–62 mph	4.8–8.2 s	2.9–4.7 s (better)
Top speed
Top speed	147–155 mph	173–197 mph (better)
Engine or motors
Engine or motors	420i: 1,998 cc four-cylinder turbo petrol, 135 kW (184 hp); M440i xDrive: 2,998 cc six-cylinder turbo petrol with 48 V mild hybrid, 288 kW (392 hp); bhp converted from BMW's kW figures	SL 43: 1,991 cc four-cylinder turbo petrol, 310 kW (421 hp) plus 10 kW mild-hybrid drive; SL 55 and SL 63: 3,982 cc V8, 350 or 430 kW (476 or 585 hp); SL 63 S E PERFORMANCE: 450 kW V8 plus 150 kW electric motor, 600 kW (816 hp) system output; bhp converted from Mercedes' kW figures
Torque
Torque	300 Nm (420i), 540 Nm (M440i xDrive)	500 Nm (SL 43), 700 Nm (SL 55), 800 Nm (SL 63), 850 Nm plus 320 Nm electric (SL 63 S E PERFORMANCE)
Gearbox
Gearbox	8-speed automatic	AMG SPEEDSHIFT MCT 9-speed
Drive
Drive	Rear-wheel drive (420i) or all-wheel drive (M440i xDrive)	Rear-wheel drive (SL 43); 4MATIC+ all-wheel drive (SL 55, SL 63 and SL 63 S E PERFORMANCE)
Range and charging
Zero-emission range (WLTP)
Zero-emission range (WLTP)	–	7 miles
Battery
Battery	–	4.84 kWh
Economy (WLTP)
Economy (WLTP)	39.2–41.5 mpg (better)	21.7–31.4 mpg
Range detail
Range detail	–	SL 63 S E PERFORMANCE WLTP electric range 7 miles
Charging
Charging	–	SL 63 S E PERFORMANCE: 4.84 kWh lithium-ion battery; 3.7 kW AC, 25–100% in 1 hour 30 minutes
Efficiency
Efficiency	WLTP combined: 40.9–41.5 mpg (420i), 36.7–39.2 mpg (M440i xDrive)	WLTP combined: 31.4 mpg (SL 43, Mercedes UK technical data; 29.7–31.4 mpg in the brochure), 21.1–21.7 mpg (SL 55, SL 63), 28.3 mpg and 336 Wh/km (SL 63 S E PERFORMANCE)
CO2 emissions
CO2 emissions	154–158 g/km (420i), 164–175 g/km (M440i xDrive), WLTP combined	206 g/km (SL 43), 305 g/km (SL 55, SL 63), 228 g/km (SL 63 S E PERFORMANCE)
Practicality
Body
Body	Convertible	Convertible
Seats
Seats	4	4
Boot
Boot	385 litres (better)	213 litres
Length
Length	4,768 mm	4,700 mm
Width
Width	1,852 mm	1,915 mm
Weight
Weight	–	From 1,837 kg
Boot
Boot	385 litres	213 litres; 110 litres (SL 63 S E PERFORMANCE)
Towing
Towing	Up to 1,600 kg braked (420i), 1,800 kg (M440i xDrive)	–
Size
Size	4,768 mm long (4,770 mm M440i), 1,852 mm wide (2,081 mm with mirrors), 1,384 mm high (1,394 mm M440i); 2,851 mm wheelbase; EC unladen weight including a 75 kg driver is 1,765 kg (420i), 2,000 kg (current M440i xDrive)	4,700 mm long, 1,915 mm wide without mirrors (2,100 mm with), 1,359 mm high; 13.05 m turning circle (12.35 m V8 models); kerb weight 1,837 kg (SL 43, Mercedes UK technical data) to 2,199–2,215 kg (SL 63 S E PERFORMANCE, brochure, including a 75 kg driver); 70-litre fuel tank