Car comparison

BMW 4 Series Coupe (G22) 420ivsBMW 4 Series Convertible (G23) 420i

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

New comparison

BMW 4 Series Coupe (G22)

420i

184 hp1998 ccGasolineRWDAutomaticTurbochargedCoupe2020-2024
VS

BMW 4 Series Convertible (G23)

420i

184 hp1998 ccGasolineRWDAutomaticTurbochargedCabriolet / convertible2020-2024

Comparison overview

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

Best choices

BMW 4 Series Coupe (G22) 420i

  • Quickest 0-100 km/h
    7.5 s
  • Fastest top speed
    240 km/h
    149 mph
  • Most powerful
    184 hp
    137 kW
  • Highest torque
    300 Nm
    221 lb-ft
  • Lightest
    1,525 kg
    3,362 lb
  • Best power-to-weight
    121 hp/t
    90 kW/t
    8.3 kg/hp
  • Lowest combined fuel consumption
    5.8 L/100 km
    40.6 mpg US
    48.7 mpg UK
  • Lowest city consumption
    7.2 L/100 km
    32.7 mpg US
    39.2 mpg UK
  • Lowest highway consumption
    5.0 L/100 km
    47.0 mpg US
    56.5 mpg UK
  • Best estimated range
    1,017 km
    632 mi
  • Largest trunk
    440 L
  • Best overall score
    52/100
  • Best performance score
    52/100
  • Best economy score
    91/100
  • Best practicality score
    53/100

Specification comparison

Specification comparison
ModelBMW4 Series Coupe (G22)420iBMW4 Series Convertible (G23)420i
Power
184hp137kW
184hp137kW
Torque
300Nm221lb-ft
300Nm221lb-ft
Curb weight
1,525kg3,362lb
1,690kg3,726lb
Gross weight
2,015kg4,442lb
2,185kg4,817lb
Top speed
240 km/h
149 mph
236 km/h
147 mph
To 99% top speed
92.8s99% target: 238 km/h / 148 mph
Calculated
107.5s99% target: 234 km/h / 145 mph
Calculated
0-100 km/h
7.5s
8.2s
0-200 km/h
30.7s
Calculated
36.3s
Calculated
0-60 mph
7.1s
Calculated
7.8s
Calculated
Fuel consumption
5.8L/100 km40.6mpg US48.7mpg UK
6.1L/100 km38.6mpg US46.3mpg UK
Fuel consumption city
7.2L/100 km32.7mpg US39.2mpg UK
7.4L/100 km31.8mpg US38.2mpg UK
Fuel consumption highway
5L/100 km47mpg US56.5mpg UK
5.4L/100 km43.6mpg US52.3mpg UK
Quarter mile
15.4s
Calculated
15.9s
Calculated
Power-to-weight
121hp/t90kW/t55hp/1000 lb
Calculated
109hp/t81kW/t49hp/1000 lb
Calculated
Torque-to-weight
197Nm/t132lb-ft/ton
Calculated
178Nm/t119lb-ft/ton
Calculated
Estimated range
1,017km632mi
Calculated
967km601mi
Calculated
Displacement
1,998cc122cu in
1,998cc122cu in
Length
4,768mm188in
4,768mm188in
Width
1,852mm73in
1,852mm73in
Height
1,383mm54in
1,384mm54in
Wheelbase
2,851mm112in
2,851mm112in
Front track
1,575mm62in
1,575mm62in
Rear track
1,611mm63in
1,611mm63in
Ground clearance
127mm5in
124mm5in
Trunk volume
440L
300L
Max trunk volume-
385L
Doors
2
2
Seats
4
4
Fuel tank
59L
59L

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 Coupe (G22) 420iBMW 4 Series Convertible (G23) 420iPowerTorque
  • BMW 4 Series Coupe (G22) 420i: Power / Torque
  • BMW 4 Series Convertible (G23) 420i: Power / Torque
Dyno simulation data table
VehiclePeak power RPMPeak torque RPMMax engine speed
BMW4 Series Coupe (G22)420i5,000-6,500 rpm1,350-4,000 rpm6,750 rpm
BMW4 Series Convertible (G23)420i5,000-6,500 rpm1,350-4,000 rpm6,750 rpm

Acceleration curve

Estimated speed over time for selected vehicles.

Acceleration and drag-race table
MetricBMW4 Series Coupe (G22)420iBMW4 Series Convertible (G23)420i
Acceleration checkpoints
0-60 mph
0-97 km/h
7.1 s
7.8 s
0-100 km/h
0-62 mph
7.5 s
8.2 s
0-200 km/h
0-124 mph
30.7 s
36.3 s
Top speed
240 km/h
149 mph
236 km/h
147 mph
Drag race simulation
60 ft
18 m
2.5 s
2.6 s
330 ft
101 m
6.7 s
6.9 s
1/8 mile
201 m
10.1 s
10.4 s
1000 ft
305 m
13.0 s
13.4 s
1/4 mile
402 m
15.4 s
15.9 s
Trap speed
1/4 mile
402 m
151 km/h
94 mph
145 km/h
90 mph

Power comparison

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

Chart data table
VehicleValue
BMW4 Series Coupe (G22)420i
184 hp
137 kW
BMW4 Series Convertible (G23)420i
184 hp
137 kW

Torque comparison

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

Chart data table
VehicleValue
BMW4 Series Coupe (G22)420i
300 Nm
221 lb-ft
BMW4 Series Convertible (G23)420i
300 Nm
221 lb-ft

Curb weight comparison

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

Chart data table
VehicleValue
BMW4 Series Coupe (G22)420i
1,525 kg
3,362 lb
BMW4 Series Convertible (G23)420i
1,690 kg
3,726 lb

Top speed without limiter comparison

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

Chart data table
VehicleValue
BMW4 Series Coupe (G22)420i
240 km/h
149 mph
BMW4 Series Convertible (G23)420i
236 km/h
147 mph

0-100 km/h comparison

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

The biggest 0-100 km/h difference is between BMW 4 Series Coupe (G22) 420i and BMW 4 Series Convertible (G23) 420i: 0.7 s.

Fuel consumption comparison

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

Chart data table
VehicleValue
BMW4 Series Coupe (G22)420i
5.8 L/100 km
40.6 mpg US
48.7 mpg UK
BMW4 Series Convertible (G23)420i
6.1 L/100 km
38.6 mpg US
46.3 mpg UK

Power-to-weight comparison

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

Chart data table
VehicleValue
BMW4 Series Coupe (G22)420i
121 hp/t
90 kW/t
8.3 kg/hp
BMW4 Series Convertible (G23)420i
109 hp/t
81 kW/t
9.2 kg/hp

Estimated range comparison

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

Chart data table
VehicleValue
BMW4 Series Coupe (G22)420i
1,017 km
632 mi
BMW4 Series Convertible (G23)420i
967 km
601 mi

Performance spider chart

Radar chart comparing normalized performance and fuel-consumption scores.

Chart data table
VehiclePowerAccelerationTop speed
BMW4 Series Coupe (G22)420i
184 hp
137 kW
7.5 s
240 km/h
149 mph
BMW4 Series Convertible (G23)420i
184 hp
137 kW
8.2 s
236 km/h
147 mph

Most attractive quadrant

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

Chart data table
VehiclePerformance scorePracticality score
BMW4 Series Coupe (G22)420i
Power
184 hp
137 kW
0-100 km/h7.5 s
Top speed
240 km/h
149 mph
Doors/seats
2 doors
4 seats
Trunk
440 L
15.5 cu ft
Length
4,768 mm
187.7 in
Height
1,383 mm
54.4 in
BMW4 Series Convertible (G23)420i
Power
184 hp
137 kW
0-100 km/h8.2 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

Performance vs fuel economy

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

Performance vs fuel economy data table
VehiclePerformance scoreFuel economy score
BMW4 Series Coupe (G22)420i
Power
184 hp
137 kW
0-100 km/h7.5 s
Top speed
240 km/h
149 mph
5.8 L/100 km
40.6 mpg US
48.7 mpg UK
BMW4 Series Convertible (G23)420i
Power
184 hp
137 kW
0-100 km/h8.2 s
Top speed
236 km/h
147 mph
6.1 L/100 km
38.6 mpg US
46.3 mpg UK

BMW 4 Series Coupe (G22) 420i 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
VehicleFuel consumption, L/100 km0-100 km/h, s
BMW4 Series Coupe (G22)420i
5.8 L/100 km
40.6 mpg US
48.7 mpg UK
7.5 s
BMW4 Series Convertible (G23)420i
6.1 L/100 km
38.6 mpg US
46.3 mpg UK
8.2 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
VehiclePower-to-weight, hp/tFuel consumption, L/100 km
BMW4 Series Coupe (G22)420i
121 hp/t
90 kW/t
8.3 kg/hp
5.8 L/100 km
40.6 mpg US
48.7 mpg UK
BMW4 Series Convertible (G23)420i
109 hp/t
81 kW/t
9.2 kg/hp
6.1 L/100 km
38.6 mpg US
46.3 mpg UK

Detailed score breakdown

Detailed score breakdown
VehicleBMW4 Series Coupe (G22)420iBMW4 Series Convertible (G23)420i
Power
184 hp
137 kW
184 hp
137 kW
Torque
300 Nm
221 lb-ft
300 Nm
221 lb-ft
Acceleration
7.5 s
8.2 s
Top speed
240 km/h
149 mph
236 km/h
147 mph
Lightness
1,525 kg
3,362 lb
1,690 kg
3,726 lb
Fuel consumption
5.8 L/100 km
40.6 mpg US
48.7 mpg UK
6.1 L/100 km
38.6 mpg US
46.3 mpg UK
Practicality
Doors/seats
2 doors
4 seats
Trunk
440 L
15.5 cu ft
Length
4,768 mm
187.7 in
Height
1,383 mm
54.4 in
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
Range score
1,017 km
632 mi
967 km
601 mi
Trunk score
440 L
15.5 cu ft
300 L
10.6 cu ft
Power-to-weight score
121 hp/t
90 kW/t
8.3 kg/hp
109 hp/t
81 kW/t
9.2 kg/hp
Overall
Fixed score
Fixed score

Fuel cost and annual usage

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

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
VehicleBMW 4 Series Coupe (G22) 420iBMW 4 Series Convertible (G23) 420i
Consumption5.8 L/100 km40.6 mpg US48.7 mpg UK6.1 L/100 km38.6 mpg US46.3 mpg UK
Cost / 100 km10.15 LC100 km10.67 LC100 km
Cost / 100 mi16.33 LC100 mi17.18 LC100 mi
Annual fuel used870 L230 US gal191 UK gal915 L242 US gal201 UK gal
Annual fuel cost1,523 LC/year1,601 LC/year

Head-to-head comparisons

BMW 4 Series Coupe (G22) 420i

  • Is 165 kg lighter
  • Is 0.7 s quicker from 0-100 km/h
  • Has 4 km/h (2 mph) higher top speed
  • Uses 0.3 L/100 km less fuel
  • Has 12 hp/t better power-to-weight
  • Has 50 km (31 mi) more estimated range
  • Has 140 L more trunk volume

Pros

  • Quickest 0-100 km/h in this comparison
  • Highest top speed
  • Most powerful
  • Highest torque
  • Lightest
  • Lowest combined fuel consumption
  • Best power-to-weight ratio
  • Best estimated range
  • Largest trunk

BMW 4 Series Convertible (G23) 420i

No measurable advantages in the available data.

Cons

  • Slowest 0-100 km/h
  • Highest combined fuel consumption
  • Heaviest
  • Lowest top speed
  • Smallest trunk

Choose cars to compare

Brand
Model
Generation
Engine or modification
BMW 4 Series Coupe (G22) 420i
BMW 4 Series Convertible (G23) 420i
Compare selected cars
2 vehicles selected

Popular comparisons

BMW 4 Series Coupe (G22) 420i vs BMW 4 Series Convertible (G23) 420i - car comparison - FastVsFaster