Car comparison

BMW 4 Series Convertible (G23) 420ivsBMW 4 Series Gran Coupe (F36) 420d

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

New comparison

BMW 4 Series Convertible (G23)

420i

184 hp1998 ccGasolineRWDAutomaticTurbochargedCabriolet / convertible2020-2024
VS

BMW 4 Series Gran Coupe (F36)

420d

184 hp1995 ccDieselRWDAutomaticTurbochargedCoupe2014-2015

Comparison overview

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

Best choices

BMW 4 Series Gran Coupe (F36) 420d

  • Quickest 0-100 km/h
    7.5 s
  • Highest torque
    380 Nm
    280 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
    4.6 L/100 km
    51.1 mpg US
    61.4 mpg UK
  • Lowest city consumption
    5.4 L/100 km
    43.6 mpg US
    52.3 mpg UK
  • Lowest highway consumption
    4.1 L/100 km
    57.4 mpg US
    68.9 mpg UK
  • Best estimated range
    1,239 km
    770 mi
  • Largest trunk
    480 L
  • Best overall score
    57/100
  • Best performance score
    52/100
  • Best economy score
    94/100
  • Best practicality score
    68/100

Specification comparison

Specification comparison
ModelBMW4 Series Convertible (G23)420iBMW4 Series Gran Coupe (F36)420d
Power
184hp137kW
184hp137kW
Torque
300Nm221lb-ft
380Nm280lb-ft
Curb weight
1,690kg3,726lb
1,525kg3,362lb
Gross weight
2,185kg4,817lb
2,085kg4,597lb
Top speed
236 km/h
147 mph
231 km/h
144 mph
To 99% top speed
107.5s99% target: 234 km/h / 145 mph
Calculated
90.7s99% target: 229 km/h / 142 mph
Calculated
0-100 km/h
8.2s
7.5s
0-200 km/h
36.3s
Calculated
33.8s
Calculated
0-60 mph
7.8s
Calculated
7.1s
Calculated
Fuel consumption
6.1L/100 km38.6mpg US46.3mpg UK
4.6L/100 km51.1mpg US61.4mpg UK
Fuel consumption city
7.4L/100 km31.8mpg US38.2mpg UK
5.4L/100 km43.6mpg US52.3mpg UK
Fuel consumption highway
5.4L/100 km43.6mpg US52.3mpg UK
4.1L/100 km57.4mpg US68.9mpg UK
Quarter mile
15.9s
Calculated
15.4s
Calculated
Power-to-weight
109hp/t81kW/t49hp/1000 lb
Calculated
121hp/t90kW/t55hp/1000 lb
Calculated
Torque-to-weight
178Nm/t119lb-ft/ton
Calculated
249Nm/t167lb-ft/ton
Calculated
Estimated range
967km601mi
Calculated
1,239km770mi
Calculated
Displacement
1,998cc122cu in
1,995cc122cu in
Length
4,768mm188in
4,638mm183in
Width
1,852mm73in
1,825mm72in
Height
1,384mm54in
1,389mm55in
Wheelbase
2,851mm112in
2,810mm111in
Front track
1,575mm62in
1,545mm61in
Rear track
1,611mm63in
1,594mm63in
Ground clearance
124mm5in
130mm5in
Trunk volume
300L
480L
Max trunk volume
385L
1,300L
Doors
2
5
Seats
4
5
Fuel tank
59L
57L
CO2 emissions-
121g/km

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) 420iBMW 4 Series Gran Coupe (F36) 420dPowerTorque
  • BMW 4 Series Convertible (G23) 420i: Power / Torque
  • BMW 4 Series Gran Coupe (F36) 420d: Power / Torque
Dyno simulation data table
VehiclePeak power RPMPeak torque RPMMax engine speed
BMW4 Series Convertible (G23)420i5,000-6,500 rpm1,350-4,000 rpm6,750 rpm
BMW4 Series Gran Coupe (F36)420d4,000 rpm1,750-2,750 rpm4,250 rpm

Acceleration curve

Estimated speed over time for selected vehicles.

Acceleration and drag-race table
MetricBMW4 Series Convertible (G23)420iBMW4 Series Gran Coupe (F36)420d
Acceleration checkpoints
0-60 mph
0-97 km/h
7.8 s
7.1 s
0-100 km/h
0-62 mph
8.2 s
7.5 s
0-200 km/h
0-124 mph
36.3 s
33.8 s
Top speed
236 km/h
147 mph
231 km/h
144 mph
Drag race simulation
60 ft
18 m
2.6 s
2.5 s
330 ft
101 m
6.9 s
6.7 s
1/8 mile
201 m
10.4 s
10.0 s
1000 ft
305 m
13.4 s
13.0 s
1/4 mile
402 m
15.9 s
15.4 s
Trap speed
1/4 mile
402 m
145 km/h
90 mph
149 km/h
93 mph

Power comparison

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

Chart data table
VehicleValue
BMW4 Series Convertible (G23)420i
184 hp
137 kW
BMW4 Series Gran Coupe (F36)420d
184 hp
137 kW

Torque comparison

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

Chart data table
VehicleValue
BMW4 Series Convertible (G23)420i
300 Nm
221 lb-ft
BMW4 Series Gran Coupe (F36)420d
380 Nm
280 lb-ft

Curb weight comparison

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

Chart data table
VehicleValue
BMW4 Series Convertible (G23)420i
1,690 kg
3,726 lb
BMW4 Series Gran Coupe (F36)420d
1,525 kg
3,362 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 Convertible (G23)420i
236 km/h
147 mph
BMW4 Series Gran Coupe (F36)420d
231 km/h
144 mph

0-100 km/h comparison

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

Chart data table
VehicleValue
BMW4 Series Convertible (G23)420i8.2 s
BMW4 Series Gran Coupe (F36)420d7.5 s

The biggest 0-100 km/h difference is between BMW 4 Series Gran Coupe (F36) 420d 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 Convertible (G23)420i
6.1 L/100 km
38.6 mpg US
46.3 mpg UK
BMW4 Series Gran Coupe (F36)420d
4.6 L/100 km
51.1 mpg US
61.4 mpg UK

The biggest fuel consumption difference is between BMW 4 Series Gran Coupe (F36) 420d and BMW 4 Series Convertible (G23) 420i: 1.5 L/100 km.

Power-to-weight comparison

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

Chart data table
VehicleValue
BMW4 Series Convertible (G23)420i
109 hp/t
81 kW/t
9.2 kg/hp
BMW4 Series Gran Coupe (F36)420d
121 hp/t
90 kW/t
8.3 kg/hp

Estimated range comparison

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

Chart data table
VehicleValue
BMW4 Series Convertible (G23)420i
967 km
601 mi
BMW4 Series Gran Coupe (F36)420d
1,239 km
770 mi

Performance spider chart

Radar chart comparing normalized performance and fuel-consumption scores.

Chart data table
VehiclePowerAccelerationTop speed
BMW4 Series Convertible (G23)420i
184 hp
137 kW
8.2 s
236 km/h
147 mph
BMW4 Series Gran Coupe (F36)420d
184 hp
137 kW
7.5 s
231 km/h
144 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 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
BMW4 Series Gran Coupe (F36)420d
Power
184 hp
137 kW
0-100 km/h7.5 s
Top speed
231 km/h
144 mph
Doors/seats
5 doors
5 seats
Trunk
480 L
17.0 cu ft
Length
4,638 mm
182.6 in
Height
1,389 mm
54.7 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 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
BMW4 Series Gran Coupe (F36)420d
Power
184 hp
137 kW
0-100 km/h7.5 s
Top speed
231 km/h
144 mph
4.6 L/100 km
51.1 mpg US
61.4 mpg UK

BMW 4 Series Gran Coupe (F36) 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
VehicleFuel consumption, L/100 km0-100 km/h, s
BMW4 Series Convertible (G23)420i
6.1 L/100 km
38.6 mpg US
46.3 mpg UK
8.2 s
BMW4 Series Gran Coupe (F36)420d
4.6 L/100 km
51.1 mpg US
61.4 mpg UK
7.5 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 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
BMW4 Series Gran Coupe (F36)420d
121 hp/t
90 kW/t
8.3 kg/hp
4.6 L/100 km
51.1 mpg US
61.4 mpg UK

Detailed score breakdown

Detailed score breakdown
VehicleBMW4 Series Convertible (G23)420iBMW4 Series Gran Coupe (F36)420d
Power
184 hp
137 kW
184 hp
137 kW
Torque
300 Nm
221 lb-ft
380 Nm
280 lb-ft
Acceleration
8.2 s
7.5 s
Top speed
236 km/h
147 mph
231 km/h
144 mph
Lightness
1,690 kg
3,726 lb
1,525 kg
3,362 lb
Fuel consumption
6.1 L/100 km
38.6 mpg US
46.3 mpg UK
4.6 L/100 km
51.1 mpg US
61.4 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
480 L
17.0 cu ft
Length
4,638 mm
182.6 in
Height
1,389 mm
54.7 in
Range score
967 km
601 mi
1,239 km
770 mi
CO2 score
-
121 g/km
Trunk score
300 L
10.6 cu ft
480 L
17.0 cu ft
Power-to-weight score
109 hp/t
81 kW/t
9.2 kg/hp
121 hp/t
90 kW/t
8.3 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 Convertible (G23) 420iBMW 4 Series Gran Coupe (F36) 420d
Consumption6.1 L/100 km38.6 mpg US46.3 mpg UK4.6 L/100 km51.1 mpg US61.4 mpg UK
Cost / 100 km10.67 LC100 km8.05 LC100 km
Cost / 100 mi17.18 LC100 mi12.96 LC100 mi
Annual fuel used915 L242 US gal201 UK gal690 L182 US gal152 UK gal
Annual fuel cost1,601 LC/year1,208 LC/year

Head-to-head comparisons

BMW 4 Series Convertible (G23) 420i

  • Has 5 km/h (3 mph) higher top speed

Pros

  • Highest top speed
  • Most powerful

Cons

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

BMW 4 Series Gran Coupe (F36) 420d

  • Has 80 Nm more
  • Is 165 kg lighter
  • Is 0.7 s quicker from 0-100 km/h
  • Uses 1.5 L/100 km less fuel
  • Has 12 hp/t better power-to-weight
  • Has 272 km (169 mi) more estimated range
  • Has 180 L more trunk volume

Pros

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

Cons

  • Lowest top speed

Choose cars to compare

Brand
Model
Generation
Engine or modification
BMW 4 Series Convertible (G23) 420i
BMW 4 Series Gran Coupe (F36) 420d
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