Car comparison

BMW 6 Series Convertible (F12) 640ivsBMW X4 (F26) 35i

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

New comparison

BMW 6 Series Convertible (F12)

640i

320 hp2979 ccGasolineAWDAutomaticTurbochargedCabriolet / convertible2013-2015
VS

BMW X4 (F26)

35i

306 hp2979 ccGasolineAWDAutomaticTurbocharged2014-2018

Comparison overview

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

Best choices

BMW X4 (F26) 35i

  • Lightest
    1,815 kg
    4,001 lb
  • Best power-to-weight
    169 hp/t
    126 kW/t
    5.9 kg/hp
  • Lowest combined fuel consumption
    8.3 L/100 km
    28.3 mpg US
    34.0 mpg UK
  • Lowest city consumption
    10.7 L/100 km
    22.0 mpg US
    26.4 mpg UK
  • Lowest CO2 emissions
    193 g/km
  • Largest trunk
    500 L
  • Best overall score
    67/100
  • Best economy score
    85/100
  • Best practicality score
    75/100

BMW 6 Series Convertible (F12) 640i

  • Quickest 0-100 km/h
    5.4 s
  • Fastest top speed
    260 km/h
    162 mph Unrestricted
    250 km/h
    155 mph Restricted
  • Most powerful
    320 hp
    239 kW
  • Highest torque
    450 Nm
    332 lb-ft
  • Lowest highway consumption
    6.6 L/100 km
    35.6 mpg US
    42.8 mpg UK
  • Best estimated range
    833 km
    518 mi
  • Best performance score
    66/100

Specification comparison

Specification comparison
ModelBMW6 Series Convertible (F12)640iBMWX4 (F26)35i
Power
320hp239kW
306hp228kW
Torque
450Nm332lb-ft
400Nm295lb-ft
Curb weight
1,910kg4,211lb
1,815kg4,001lb
Gross weight
2,400kg5,291lb
2,405kg5,302lb
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Calculated
247 km/h
153 mph
To 99% top speed
80.0s99% target: 257 km/h / 160 mph
Calculated
81.6s99% target: 245 km/h / 152 mph
Calculated
0-100 km/h
5.4s
5.5s
0-200 km/h
20.3s
Calculated
23.1s
Calculated
0-60 mph
5.1s
Calculated
5.2s
Calculated
Fuel consumption
8.4L/100 km28mpg US33.6mpg UK
8.3L/100 km28.3mpg US34.0mpg UK
Fuel consumption city
11.4L/100 km20.6mpg US24.8mpg UK
10.7L/100 km22mpg US26.4mpg UK
Fuel consumption highway
6.6L/100 km35.6mpg US42.8mpg UK
6.9L/100 km34.1mpg US40.9mpg UK
Quarter mile
13.6s
Calculated
13.7s
Calculated
Power-to-weight
168hp/t125kW/t76hp/1000 lb
Calculated
169hp/t126kW/t76hp/1000 lb
Calculated
Torque-to-weight
236Nm/t158lb-ft/ton
Calculated
220Nm/t147lb-ft/ton
Calculated
Estimated range
833km518mi
Calculated
807km502mi
Calculated
Displacement
2,979cc182cu in
2,979cc182cu in
Length
4,894mm193in
4,671mm184in
Width
1,894mm75in
1,881mm74in
Height
1,365mm54in
1,624mm64in
Wheelbase
2,855mm112in
2,810mm111in
Front track
1,600mm63in
1,616mm64in
Rear track
1,665mm66in
1,632mm64in
Ground clearance
123mm5in
204mm8in
Trunk volume
300L
500L
Max trunk volume
350L
1,400L
Doors
2
5
Seats
4
5
Fuel tank
70L
67L
CO2 emissions
195g/km
193g/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 6 Series Convertible (F12) 640iBMW X4 (F26) 35iPowerTorque
  • BMW 6 Series Convertible (F12) 640i: Power / Torque
  • BMW X4 (F26) 35i: Power / Torque
Dyno simulation data table
VehiclePeak power RPMPeak torque RPMMax engine speed
BMW6 Series Convertible (F12)640i5,800-6,000 rpm1,300-4,500 rpm6,250 rpm
BMWX4 (F26)35i5,800-6,400 rpm1,200-5,000 rpm6,650 rpm

Acceleration curve

Estimated speed over time for selected vehicles.

Acceleration and drag-race table
MetricBMW6 Series Convertible (F12)640iBMWX4 (F26)35i
Acceleration checkpoints
0-60 mph
0-97 km/h
5.1 s
5.2 s
0-100 km/h
0-62 mph
5.4 s
5.5 s
0-200 km/h
0-124 mph
20.3 s
23.1 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Likely limited
247 km/h
153 mph
Drag race simulation
60 ft
18 m
2.2 s
2.1 s
330 ft
101 m
5.8 s
5.8 s
1/8 mile
201 m
8.8 s
8.9 s
1000 ft
305 m
11.4 s
11.5 s
1/4 mile
402 m
13.6 s
13.7 s
Trap speed
1/4 mile
402 m
169 km/h
105 mph
164 km/h
102 mph

Power comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (F12)640i
320 hp
239 kW
BMWX4 (F26)35i
306 hp
228 kW

BMW 6 Series Convertible (F12) 640i has 14 hp more than BMW X4 (F26) 35i.

The biggest power difference is between BMW X4 (F26) 35i and BMW 6 Series Convertible (F12) 640i: 14 hp (10 kW).

Torque comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (F12)640i
450 Nm
332 lb-ft
BMWX4 (F26)35i
400 Nm
295 lb-ft

Curb weight comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (F12)640i
1,910 kg
4,211 lb
BMWX4 (F26)35i
1,815 kg
4,001 lb

Top speed without limiter comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (F12)640i
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
BMWX4 (F26)35i
247 km/h
153 mph

0-100 km/h comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (F12)640i5.4 s
BMWX4 (F26)35i5.5 s

The biggest 0-100 km/h difference is between BMW 6 Series Convertible (F12) 640i and BMW X4 (F26) 35i: 0.1 s.

Fuel consumption comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (F12)640i
8.4 L/100 km
28.0 mpg US
33.6 mpg UK
BMWX4 (F26)35i
8.3 L/100 km
28.3 mpg US
34.0 mpg UK

Power-to-weight comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (F12)640i
168 hp/t
125 kW/t
6.0 kg/hp
BMWX4 (F26)35i
169 hp/t
126 kW/t
5.9 kg/hp

Estimated range comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (F12)640i
833 km
518 mi
BMWX4 (F26)35i
807 km
502 mi

Performance spider chart

Radar chart comparing normalized performance and fuel-consumption scores.

Chart data table
VehiclePowerAccelerationTop speed
BMW6 Series Convertible (F12)640i
320 hp
239 kW
5.4 s
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
BMWX4 (F26)35i
306 hp
228 kW
5.5 s
247 km/h
153 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
BMW6 Series Convertible (F12)640i
Power
320 hp
239 kW
0-100 km/h5.4 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Doors/seats
2 doors
4 seats
Trunk
300 L
10.6 cu ft
Length
4,894 mm
192.7 in
Height
1,365 mm
53.7 in
BMWX4 (F26)35i
Power
306 hp
228 kW
0-100 km/h5.5 s
Top speed
247 km/h
153 mph
Doors/seats
5 doors
5 seats
Trunk
500 L
17.7 cu ft
Length
4,671 mm
183.9 in
Height
1,624 mm
63.9 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
BMW6 Series Convertible (F12)640i
Power
320 hp
239 kW
0-100 km/h5.4 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
8.4 L/100 km
28.0 mpg US
33.6 mpg UK
BMWX4 (F26)35i
Power
306 hp
228 kW
0-100 km/h5.5 s
Top speed
247 km/h
153 mph
8.3 L/100 km
28.3 mpg US
34.0 mpg UK

BMW 6 Series Convertible (F12) 640i 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
BMW6 Series Convertible (F12)640i
8.4 L/100 km
28.0 mpg US
33.6 mpg UK
5.4 s
BMWX4 (F26)35i
8.3 L/100 km
28.3 mpg US
34.0 mpg UK
5.5 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
BMW6 Series Convertible (F12)640i
168 hp/t
125 kW/t
6.0 kg/hp
8.4 L/100 km
28.0 mpg US
33.6 mpg UK
BMWX4 (F26)35i
169 hp/t
126 kW/t
5.9 kg/hp
8.3 L/100 km
28.3 mpg US
34.0 mpg UK

Detailed score breakdown

Detailed score breakdown
VehicleBMW6 Series Convertible (F12)640iBMWX4 (F26)35i
Power
320 hp
239 kW
306 hp
228 kW
Torque
450 Nm
332 lb-ft
400 Nm
295 lb-ft
Acceleration
5.4 s
5.5 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
247 km/h
153 mph
Lightness
1,910 kg
4,211 lb
1,815 kg
4,001 lb
Fuel consumption
8.4 L/100 km
28.0 mpg US
33.6 mpg UK
8.3 L/100 km
28.3 mpg US
34.0 mpg UK
Practicality
Doors/seats
2 doors
4 seats
Trunk
300 L
10.6 cu ft
Length
4,894 mm
192.7 in
Height
1,365 mm
53.7 in
Doors/seats
5 doors
5 seats
Trunk
500 L
17.7 cu ft
Length
4,671 mm
183.9 in
Height
1,624 mm
63.9 in
Range score
833 km
518 mi
807 km
502 mi
CO2 score
195 g/km
193 g/km
Trunk score
300 L
10.6 cu ft
500 L
17.7 cu ft
Power-to-weight score
168 hp/t
125 kW/t
6.0 kg/hp
169 hp/t
126 kW/t
5.9 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 6 Series Convertible (F12) 640iBMW X4 (F26) 35i
Consumption8.4 L/100 km28 mpg US33.6 mpg UK8.3 L/100 km28.3 mpg US34 mpg UK
Cost / 100 km14.70 LC100 km14.53 LC100 km
Cost / 100 mi23.66 LC100 mi23.38 LC100 mi
Annual fuel used1,260 L333 US gal277 UK gal1,245 L329 US gal274 UK gal
Annual fuel cost2,205 LC/year2,179 LC/year

Head-to-head comparisons

BMW 6 Series Convertible (F12) 640i

  • Has 14 hp more
  • Has 50 Nm more
  • Is 0.1 s quicker from 0-100 km/h
  • Has 13 km/h (8 mph) higher top speed
  • Has 26 km (16 mi) more estimated range

Pros

  • Quickest 0-100 km/h in this comparison
  • Highest top speed
  • Most powerful
  • Highest torque
  • Best estimated range

Cons

  • Highest combined fuel consumption
  • Heaviest
  • Smallest trunk
  • Highest CO2 emissions

BMW X4 (F26) 35i

  • Is 95 kg lighter
  • Uses 0.1 L/100 km less fuel
  • Has 1 hp/t better power-to-weight
  • Has 200 L more trunk volume
  • Emits 2 g/km less CO2

Pros

  • Lightest
  • Lowest combined fuel consumption
  • Best power-to-weight ratio
  • Largest trunk

Cons

  • Slowest 0-100 km/h
  • Lowest power
  • Lowest top speed

Choose cars to compare

Brand
Model
Generation
Engine or modification
BMW 6 Series Convertible (F12) 640i
BMW X4 (F26) 35i
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