Car comparison

BMW 6 Series Coupe (F13) 640ivsBMW 6 Series Convertible (E64) 645Ci

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

New comparison

BMW 6 Series Coupe (F13)

640i

320 hp2979 ccGasolineAWDAutomaticTurbochargedCoupe2013-2015
VS

BMW 6 Series Convertible (E64)

645Ci

333 hp4398 ccGasolineRWDAutomaticNaturally aspiratedCabriolet / convertible2003-2005

Comparison overview

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

Best choices

BMW 6 Series Coupe (F13) 640i

  • Quickest 0-100 km/h
    5.2 s
  • Fastest top speed
    260 km/h
    162 mph Unrestricted
    250 km/h
    155 mph Restricted
  • Highest torque
    450 Nm
    332 lb-ft
  • Lightest
    1,765 kg
    3,891 lb
  • Lowest combined fuel consumption
    8.2 L/100 km
    28.7 mpg US
    34.4 mpg UK
  • Lowest city consumption
    11.2 L/100 km
    21.0 mpg US
    25.2 mpg UK
  • Lowest highway consumption
    6.5 L/100 km
    36.2 mpg US
    43.5 mpg UK
  • Best estimated range
    854 km
    530 mi
  • Largest trunk
    460 L
  • Best overall score
    64/100
  • Best performance score
    68/100
  • Best economy score
    85/100
  • Best practicality score
    54/100

Specification comparison

Specification comparison
ModelBMW6 Series Coupe (F13)640iBMW6 Series Convertible (E64)645Ci
Power
320hp239kW
333hp248kW
Torque
450Nm332lb-ft
450Nm332lb-ft
Curb weight
1,765kg3,891lb
1,820kg4,012lb
Gross weight
2,255kg4,971lb
2,220kg4,894lb
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Calculated
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Calculated
To 99% top speed
73.6s99% target: 257 km/h / 160 mph
Calculated
88.1s99% target: 257 km/h / 160 mph
Calculated
0-100 km/h
5.2s
6.2s
0-200 km/h
19.1s
Calculated
22.8s
Calculated
0-60 mph
4.9s
Calculated
5.9s
Calculated
Fuel consumption
8.2L/100 km28.7mpg US34.4mpg UK
11.5L/100 km20.5mpg US24.6mpg UK
Fuel consumption city
11.2L/100 km21mpg US25.2mpg UK
16.8L/100 km14mpg US16.8mpg UK
Fuel consumption highway
6.5L/100 km36.2mpg US43.5mpg UK
8.5L/100 km27.7mpg US33.2mpg UK
Quarter mile
13.4s
Calculated
14.3s
Calculated
Power-to-weight
181hp/t135kW/t82hp/1000 lb
Calculated
183hp/t136kW/t83hp/1000 lb
Calculated
Torque-to-weight
255Nm/t171lb-ft/ton
Calculated
247Nm/t165lb-ft/ton
Calculated
Estimated range
854km530mi
Calculated
609km378mi
Calculated
Displacement
2,979cc182cu in
4,398cc268cu in
Length
4,894mm193in
4,820mm190in
Width
1,894mm75in
1,855mm73in
Height
1,369mm54in
1,373mm54in
Wheelbase
2,855mm112in
2,780mm109in
Front track
1,600mm63in
1,558mm61in
Rear track
1,665mm66in
1,592mm63in
Ground clearance
124mm5in
-
Trunk volume
460L
300L
Max trunk volume-
350L
Doors
2
2
Seats
4
4
Fuel tank
70L
70L
CO2 emissions
191g/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 Coupe (F13) 640iBMW 6 Series Convertible (E64) 645CiPowerTorque
  • BMW 6 Series Coupe (F13) 640i: Power / Torque
  • BMW 6 Series Convertible (E64) 645Ci: Power / Torque
Dyno simulation data table
VehiclePeak power RPMPeak torque RPMMax engine speed
BMW6 Series Coupe (F13)640i5,800-6,000 rpm1,300-4,500 rpm6,250 rpm
BMW6 Series Convertible (E64)645Ci6,100 rpm3,600 rpm6,350 rpm

Acceleration curve

Estimated speed over time for selected vehicles.

Acceleration and drag-race table
MetricBMW6 Series Coupe (F13)640iBMW6 Series Convertible (E64)645Ci
Acceleration checkpoints
0-60 mph
0-97 km/h
4.9 s
5.9 s
0-100 km/h
0-62 mph
5.2 s
6.2 s
0-200 km/h
0-124 mph
19.1 s
22.8 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Likely limited
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Likely limited
Drag race simulation
60 ft
18 m
2.2 s
2.3 s
330 ft
101 m
5.8 s
6.2 s
1/8 mile
201 m
8.7 s
9.3 s
1000 ft
305 m
11.2 s
12.0 s
1/4 mile
402 m
13.4 s
14.3 s
Trap speed
1/4 mile
402 m
172 km/h
107 mph
163 km/h
101 mph

Power comparison

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

Chart data table
VehicleValue
BMW6 Series Coupe (F13)640i
320 hp
239 kW
BMW6 Series Convertible (E64)645Ci
333 hp
248 kW

BMW 6 Series Convertible (E64) 645Ci has 13 hp more than BMW 6 Series Coupe (F13) 640i.

The biggest power difference is between BMW 6 Series Coupe (F13) 640i and BMW 6 Series Convertible (E64) 645Ci: 13 hp (10 kW).

Torque comparison

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

Chart data table
VehicleValue
BMW6 Series Coupe (F13)640i
450 Nm
332 lb-ft
BMW6 Series Convertible (E64)645Ci
450 Nm
332 lb-ft

Curb weight comparison

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

Chart data table
VehicleValue
BMW6 Series Coupe (F13)640i
1,765 kg
3,891 lb
BMW6 Series Convertible (E64)645Ci
1,820 kg
4,012 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 Coupe (F13)640i
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
BMW6 Series Convertible (E64)645Ci
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph

0-100 km/h comparison

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

Chart data table
VehicleValue
BMW6 Series Coupe (F13)640i5.2 s
BMW6 Series Convertible (E64)645Ci6.2 s

Although BMW 6 Series Convertible (E64) 645Ci has more power, BMW 6 Series Coupe (F13) 640i is quicker from 0-100 km/h.

The biggest 0-100 km/h difference is between BMW 6 Series Coupe (F13) 640i and BMW 6 Series Convertible (E64) 645Ci: 1.0 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 Coupe (F13)640i
8.2 L/100 km
28.7 mpg US
34.4 mpg UK
BMW6 Series Convertible (E64)645Ci
11.5 L/100 km
20.5 mpg US
24.6 mpg UK

The biggest fuel consumption difference is between BMW 6 Series Coupe (F13) 640i and BMW 6 Series Convertible (E64) 645Ci: 3.3 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
BMW6 Series Coupe (F13)640i
181 hp/t
135 kW/t
5.5 kg/hp
BMW6 Series Convertible (E64)645Ci
183 hp/t
136 kW/t
5.5 kg/hp

Estimated range comparison

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

Chart data table
VehicleValue
BMW6 Series Coupe (F13)640i
854 km
530 mi
BMW6 Series Convertible (E64)645Ci
609 km
378 mi

Performance spider chart

Radar chart comparing normalized performance and fuel-consumption scores.

Chart data table
VehiclePowerAccelerationTop speed
BMW6 Series Coupe (F13)640i
320 hp
239 kW
5.2 s
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
BMW6 Series Convertible (E64)645Ci
333 hp
248 kW
6.2 s
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 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 Coupe (F13)640i
Power
320 hp
239 kW
0-100 km/h5.2 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Doors/seats
2 doors
4 seats
Trunk
460 L
16.2 cu ft
Length
4,894 mm
192.7 in
Height
1,369 mm
53.9 in
BMW6 Series Convertible (E64)645Ci
Power
333 hp
248 kW
0-100 km/h6.2 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
4,820 mm
189.8 in
Height
1,373 mm
54.1 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 Coupe (F13)640i
Power
320 hp
239 kW
0-100 km/h5.2 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
8.2 L/100 km
28.7 mpg US
34.4 mpg UK
BMW6 Series Convertible (E64)645Ci
Power
333 hp
248 kW
0-100 km/h6.2 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
11.5 L/100 km
20.5 mpg US
24.6 mpg UK

BMW 6 Series Coupe (F13) 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 Coupe (F13)640i
8.2 L/100 km
28.7 mpg US
34.4 mpg UK
5.2 s
BMW6 Series Convertible (E64)645Ci
11.5 L/100 km
20.5 mpg US
24.6 mpg UK
6.2 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
BMW6 Series Coupe (F13)640i
181 hp/t
135 kW/t
5.5 kg/hp
8.2 L/100 km
28.7 mpg US
34.4 mpg UK
BMW6 Series Convertible (E64)645Ci
183 hp/t
136 kW/t
5.5 kg/hp
11.5 L/100 km
20.5 mpg US
24.6 mpg UK

Detailed score breakdown

Detailed score breakdown
VehicleBMW6 Series Coupe (F13)640iBMW6 Series Convertible (E64)645Ci
Power
320 hp
239 kW
333 hp
248 kW
Torque
450 Nm
332 lb-ft
450 Nm
332 lb-ft
Acceleration
5.2 s
6.2 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Lightness
1,765 kg
3,891 lb
1,820 kg
4,012 lb
Fuel consumption
8.2 L/100 km
28.7 mpg US
34.4 mpg UK
11.5 L/100 km
20.5 mpg US
24.6 mpg UK
Practicality
Doors/seats
2 doors
4 seats
Trunk
460 L
16.2 cu ft
Length
4,894 mm
192.7 in
Height
1,369 mm
53.9 in
Doors/seats
2 doors
4 seats
Trunk
300 L
10.6 cu ft
Length
4,820 mm
189.8 in
Height
1,373 mm
54.1 in
Range score
854 km
530 mi
609 km
378 mi
CO2 score
191 g/km
-
Trunk score
460 L
16.2 cu ft
300 L
10.6 cu ft
Power-to-weight score
181 hp/t
135 kW/t
5.5 kg/hp
183 hp/t
136 kW/t
5.5 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 Coupe (F13) 640iBMW 6 Series Convertible (E64) 645Ci
Consumption8.2 L/100 km28.7 mpg US34.4 mpg UK11.5 L/100 km20.5 mpg US24.6 mpg UK
Cost / 100 km14.35 LC100 km20.13 LC100 km
Cost / 100 mi23.09 LC100 mi32.39 LC100 mi
Annual fuel used1,230 L325 US gal271 UK gal1,725 L456 US gal379 UK gal
Annual fuel cost2,153 LC/year3,019 LC/year

Head-to-head comparisons

BMW 6 Series Coupe (F13) 640i

  • Is 55 kg lighter
  • Is 1.0 s quicker from 0-100 km/h
  • Uses 3.3 L/100 km less fuel
  • Has 245 km (152 mi) more estimated range
  • Has 160 L more trunk volume

Pros

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

Cons

  • Lowest power

BMW 6 Series Convertible (E64) 645Ci

  • Has 13 hp more
  • Has 2 hp/t better power-to-weight

Pros

  • Most powerful
  • Best power-to-weight ratio

Cons

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

Choose cars to compare

Brand
Model
Generation
Engine or modification
BMW 6 Series Coupe (F13) 640i
BMW 6 Series Convertible (E64) 645Ci
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