Car comparison

BMW 4 Series Convertible (G23) 420dvsBMW X4 (G02 LCI) · Facelift 2021 20d

Compare specs, acceleration, fuel consumption, dimensions, practicality, and estimated running costs side by side.

New comparison

BMW 4 Series Convertible (G23)

420d

190 hp1995 ccDieselRWDAutomaticTurbochargedCabriolet / convertible2020-2024

BMW X4 (G02 LCI) · Facelift 2021

20d

190 hp1995 ccDieselAWDAutomaticTurbocharged2021-2025

Comparison overview

Use the estimates as comparison hints and verify exact figures before making decisions.

BMW 4 Series Convertible (G23) 420d

Quickest 0-100 km/h
7.6 s
Fastest top speed
236 km/h
147 mph
Most powerful
190 hp
142 kW
Highest torque
400 Nm
295 lb-ft
Lightest
1,775 kg
3,913 lb
Best power-to-weight
107 hp/t
80 kW/t
9.3 kg/hp
Lowest combined fuel consumption
4.5 L/100 km
52.3 mpg US
62.8 mpg UK
Best estimated range
1,311 km
815 mi
Best performance score
52/100
Best economy score
95/100

BMW X4 (G02 LCI) Facelift 2021 20d

Largest trunk
525 L
Best overall score
57/100
Best practicality score
76/100

Specification comparison

Specification comparison
Model	BMW4 Series Convertible (G23)420d	BMWX4 (G02 LCI)Facelift 202120d
Power	190hp142kW	190hp142kW
Torque	400Nm295lb-ft	400Nm295lb-ft
Curb weight	1,775kg3,913lb	1,840kg4,057lb
Gross weight	2,270kg5,004lb	2,450kg5,401lb
Top speed	236 km/h 147 mph	213 km/h 132 mph
To 99% top speed	99.0s99% target: 234 km/h / 145 mph Calculated	95.2s99% target: 211 km/h / 131 mph Calculated
0-100 km/h	7.6s	7.9s
0-200 km/h	33.5s Calculated	50.9s Calculated
0-60 mph	7.2s Calculated	7.4s Calculated
Fuel consumption	4.5L/100 km52.3mpg US62.8mpg UK	6.5L/100 km36.2mpg US43.5mpg UK
Fuel consumption city	5L/100 km47mpg US56.5mpg UK	-
Fuel consumption highway	4.3L/100 km54.7mpg US65.7mpg UK	-
Quarter mile	15.5s Calculated	15.7s Calculated
Power-to-weight	107hp/t80kW/t49hp/1000 lb Calculated	103hp/t77kW/t47hp/1000 lb Calculated
Torque-to-weight	225Nm/t151lb-ft/ton Calculated	217Nm/t145lb-ft/ton Calculated
Estimated range	1,311km815mi Calculated	1,046km650mi Calculated
Displacement	1,995cc122cu in	1,995cc122cu in
Length	4,768mm188in	4,751mm187in
Width	1,852mm73in	1,918mm76in
Height	1,384mm54in	1,621mm64in
Wheelbase	2,851mm112in	2,864mm113in
Front track	1,575mm62in	1,620mm64in
Rear track	1,611mm63in	1,666mm66in
Ground clearance	124mm5in	204mm8in
Trunk volume	300L	525L
Max trunk volume	385L	1,430L
Doors	2	5
Seats	4	5
Fuel tank	59L	68L

Performance charts

Use the estimates as comparison hints and verify exact figures before making decisions.

Dyno simulation

Estimated stock-style power and torque curves by engine speed.

BMW 4 Series Convertible (G23) 420dBMW X4 (G02 LCI) Facelift 2021 20dPowerTorque

Dyno simulation data table
Vehicle	Peak power RPM	Peak torque RPM	Max engine speed
BMW4 Series Convertible (G23)420d	4,000 rpm	1,750-2,500 rpm	4,250 rpm
BMWX4 (G02 LCI)Facelift 202120d	4,000 rpm	1,750-2,500 rpm	4,250 rpm

Acceleration curve

Estimated speed over time for selected vehicles.

Acceleration and drag-race table
Metric	BMW4 Series Convertible (G23)420d	BMWX4 (G02 LCI)Facelift 202120d
	Acceleration checkpoints
0-60 mph 0-97 km/h	7.2 s	7.4 s
0-100 km/h 0-62 mph	7.6 s	7.9 s
0-200 km/h 0-124 mph	33.5 s	50.9 s
Top speed	236 km/h 147 mph	213 km/h 132 mph
	Drag race simulation
60 ft 18 m	2.5 s	2.4 s
330 ft 101 m	6.7 s	6.6 s
1/8 mile 201 m	10.1 s	10.1 s
1000 ft 305 m	13.0 s	13.2 s
1/4 mile 402 m	15.5 s	15.7 s
Trap speed 1/4 mile 402 m	149 km/h 92 mph	142 km/h 88 mph

Power comparison

Bar comparison chart for Power. Higher is better · hp / kW

Chart data table
Vehicle	Value
BMW4 Series Convertible (G23)420d	190 hp 142 kW
BMWX4 (G02 LCI)Facelift 202120d	190 hp 142 kW

Torque comparison

Bar comparison chart for Torque. Higher is better · Nm / lb-ft

Chart data table
Vehicle	Value
BMW4 Series Convertible (G23)420d	400 Nm 295 lb-ft
BMWX4 (G02 LCI)Facelift 202120d	400 Nm 295 lb-ft

Curb weight comparison

Bar comparison chart for Curb weight. Lower is better · kg / lb

Chart data table
Vehicle	Value
BMW4 Series Convertible (G23)420d	1,775 kg 3,913 lb
BMWX4 (G02 LCI)Facelift 202120d	1,840 kg 4,057 lb

Top speed without limiter comparison

Bar comparison chart for Top speed without limiter. Higher is better · km/h / mph

Chart data table
Vehicle	Value
BMW4 Series Convertible (G23)420d	236 km/h 147 mph
BMWX4 (G02 LCI)Facelift 202120d	213 km/h 132 mph

0-100 km/h comparison

Bar comparison chart for 0-100 km/h. Lower is better · seconds

Chart data table
Vehicle	Value
BMW4 Series Convertible (G23)420d	7.6 s
BMWX4 (G02 LCI)Facelift 202120d	7.9 s

The biggest 0-100 km/h difference is between BMW 4 Series Convertible (G23) 420d and BMW X4 (G02 LCI) Facelift 2021 20d: 0.3 s.

Fuel consumption comparison

Bar comparison chart for Fuel consumption. Lower is better · L/100 km / mpg US / mpg UK

Chart data table
Vehicle	Value
BMW4 Series Convertible (G23)420d	4.5 L/100 km 52.3 mpg US 62.8 mpg UK
BMWX4 (G02 LCI)Facelift 202120d	6.5 L/100 km 36.2 mpg US 43.5 mpg UK

The biggest fuel consumption difference is between BMW 4 Series Convertible (G23) 420d and BMW X4 (G02 LCI) Facelift 2021 20d: 2.0 L/100 km.

Power-to-weight comparison

Bar comparison chart for Power-to-weight. Higher is better · hp/t / kW/t

Chart data table
Vehicle	Value
BMW4 Series Convertible (G23)420d	107 hp/t 80 kW/t 9.3 kg/hp
BMWX4 (G02 LCI)Facelift 202120d	103 hp/t 77 kW/t 9.7 kg/hp

Estimated range comparison

Bar comparison chart for Estimated range. Higher is better · km / mi

Chart data table
Vehicle	Value
BMW4 Series Convertible (G23)420d	1,311 km 815 mi
BMWX4 (G02 LCI)Facelift 202120d	1,046 km 650 mi

Performance spider chart

Radar chart comparing normalized performance and fuel-consumption scores.

Chart data table
Vehicle	Power	Acceleration	Top speed
BMW4 Series Convertible (G23)420d	190 hp 142 kW	7.6 s	236 km/h 147 mph
BMWX4 (G02 LCI)Facelift 202120d	190 hp 142 kW	7.9 s	213 km/h 132 mph

Most attractive quadrant

Scatter chart with performance score on the X axis and practicality score on the Y axis.

Vehicle

Performance score

Practicality score

BMW4 Series Convertible (G23)420d

Power	190 hp 142 kW
0-100 km/h	7.6 s
Top speed 236 km/h 147 mph

Doors/seats	2 doors 4 seats
Trunk	300 L 10.6 cu ft
Length	4,768 mm 187.7 in
Height	1,384 mm 54.5 in

BMWX4 (G02 LCI)Facelift 202120d

Power	190 hp 142 kW
0-100 km/h	7.9 s
Top speed 213 km/h 132 mph

Doors/seats	5 doors 5 seats
Trunk	525 L 18.5 cu ft
Length	4,751 mm 187.0 in
Height	1,621 mm 63.8 in

Performance vs fuel economy

Cars closer to the top-right corner combine stronger performance with better fuel economy scores.

Vehicle

Performance score

Fuel economy score

BMW4 Series Convertible (G23)420d

Power	190 hp 142 kW
0-100 km/h	7.6 s
Top speed 236 km/h 147 mph

4.5 L/100 km

52.3 mpg US

62.8 mpg UK

BMWX4 (G02 LCI)Facelift 202120d

Power	190 hp 142 kW
0-100 km/h	7.9 s
Top speed 213 km/h 132 mph

6.5 L/100 km

36.2 mpg US

43.5 mpg UK

BMW 4 Series Convertible (G23) 420d is closest to the top-right balance target for performance and fuel economy.

Acceleration vs fuel consumption

Cars closer to the lower-left corner offer a better mix of quick acceleration and low fuel consumption.

Acceleration vs fuel consumption data table
Vehicle	Fuel consumption, L/100 km	0-100 km/h, s
BMW4 Series Convertible (G23)420d	4.5 L/100 km 52.3 mpg US 62.8 mpg UK	7.6 s
BMWX4 (G02 LCI)Facelift 202120d	6.5 L/100 km 36.2 mpg US 43.5 mpg UK	7.9 s

Power-to-weight vs fuel consumption

The shaded area favors higher power-to-weight with lower combined fuel consumption.

Power-to-weight vs fuel consumption data table
Vehicle	Power-to-weight, hp/t	Fuel consumption, L/100 km
BMW4 Series Convertible (G23)420d	107 hp/t 80 kW/t 9.3 kg/hp	4.5 L/100 km 52.3 mpg US 62.8 mpg UK
BMWX4 (G02 LCI)Facelift 202120d	103 hp/t 77 kW/t 9.7 kg/hp	6.5 L/100 km 36.2 mpg US 43.5 mpg UK

Detailed score breakdown

Vehicle

BMW4 Series Convertible (G23)420d

BMWX4 (G02 LCI)Facelift 202120d

Power

190 hp

142 kW

190 hp

142 kW

Torque

400 Nm

295 lb-ft

400 Nm

295 lb-ft

Acceleration

7.6 s

7.9 s

Top speed

236 km/h

147 mph

213 km/h

132 mph

Lightness

1,775 kg

3,913 lb

1,840 kg

4,057 lb

Fuel consumption

4.5 L/100 km

52.3 mpg US

62.8 mpg UK

6.5 L/100 km

36.2 mpg US

43.5 mpg UK

Practicality

Doors/seats	2 doors 4 seats
Trunk	300 L 10.6 cu ft
Length	4,768 mm 187.7 in
Height	1,384 mm 54.5 in

Doors/seats	5 doors 5 seats
Trunk	525 L 18.5 cu ft
Length	4,751 mm 187.0 in
Height	1,621 mm 63.8 in

Range score

1,311 km

815 mi

1,046 km

650 mi

Trunk score

300 L

10.6 cu ft

525 L

18.5 cu ft

Power-to-weight score

107 hp/t

80 kW/t

9.3 kg/hp

103 hp/t

77 kW/t

9.7 kg/hp

Overall

Fixed score

Fuel cost and annual usage

Estimate running costs from combined consumption, your annual distance, and the fuel price in your local currency.

Average annual distanceDistance unitFuel price in your local currencyPrice unit

Enter the fuel price in your local currency, for example €/L, $/gal, £/L or any other local currency.

LC = Local Currency

Fuel cost and annual usage
Vehicle	BMW 4 Series Convertible (G23) 420d	BMW X4 (G02 LCI) Facelift 2021 20d
Consumption	4.5 L/100 km52.3 mpg US62.8 mpg UK	6.5 L/100 km36.2 mpg US43.5 mpg UK
Cost / 100 km	7.88 LC100 km	11.38 LC100 km
Cost / 100 mi	12.67 LC100 mi	18.31 LC100 mi
Annual fuel used	675 L178 US gal148 UK gal	975 L258 US gal214 UK gal
Annual fuel cost	1,181 LC/year	1,706 LC/year