Car comparison

BMW 6 Series Convertible (E64) 645CivsBMW 6 Series Gran Turismo (G32) 620d

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

New comparison

BMW 6 Series Convertible (E64)

645Ci

333 hp4398 ccGasolineRWDAutomaticNaturally aspiratedCabriolet / convertible2003-2005
VS

BMW 6 Series Gran Turismo (G32)

620d

190 hp1995 ccDieselRWDAutomaticTurbocharged2018-2020

Comparison overview

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

Best choices

BMW 6 Series Gran Turismo (G32) 620d

  • Lightest
    1,765 kg
    3,891 lb
  • Lowest combined fuel consumption
    4.9 L/100 km
    48.0 mpg US
    57.6 mpg UK
  • Lowest city consumption
    5.4 L/100 km
    43.6 mpg US
    52.3 mpg UK
  • Lowest highway consumption
    4.6 L/100 km
    51.1 mpg US
    61.4 mpg UK
  • Best estimated range
    1,347 km
    837 mi
  • Largest trunk
    610 L
  • Best overall score
    60/100
  • Best economy score
    94/100
  • Best practicality score
    79/100

BMW 6 Series Convertible (E64) 645Ci

  • Quickest 0-100 km/h
    6.2 s
  • Fastest top speed
    260 km/h
    162 mph Unrestricted
    250 km/h
    155 mph Restricted
  • Most powerful
    333 hp
    248 kW
  • Highest torque
    450 Nm
    332 lb-ft
  • Best power-to-weight
    183 hp/t
    136 kW/t
    5.5 kg/hp
  • Best performance score
    65/100

Specification comparison

Specification comparison
ModelBMW6 Series Convertible (E64)645CiBMW6 Series Gran Turismo (G32)620d
Power
333hp248kW
190hp142kW
Torque
450Nm332lb-ft
400Nm295lb-ft
Curb weight
1,820kg4,012lb
1,765kg3,891lb
Gross weight
2,220kg4,894lb
2,440kg5,379lb
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Calculated
Unrestricted
230 km/h143 mph
Restricted
220 km/h137 mph
Calculated
To 99% top speed
88.1s99% target: 257 km/h / 160 mph
Calculated
97.1s99% target: 228 km/h / 141 mph
Calculated
0-100 km/h
6.2s
7.9s
0-200 km/h
22.8s
Calculated
36.5s
Calculated
0-60 mph
5.9s
Calculated
7.5s
Calculated
Fuel consumption
11.5L/100 km20.5mpg US24.6mpg UK
4.9L/100 km48mpg US57.6mpg UK
Fuel consumption city
16.8L/100 km14mpg US16.8mpg UK
5.4L/100 km43.6mpg US52.3mpg UK
Fuel consumption highway
8.5L/100 km27.7mpg US33.2mpg UK
4.6L/100 km51.1mpg US61.4mpg UK
Quarter mile
14.3s
Calculated
15.7s
Calculated
Power-to-weight
183hp/t136kW/t83hp/1000 lb
Calculated
108hp/t80kW/t49hp/1000 lb
Calculated
Torque-to-weight
247Nm/t165lb-ft/ton
Calculated
227Nm/t152lb-ft/ton
Calculated
Estimated range
609km378mi
Calculated
1,347km837mi
Calculated
Displacement
4,398cc268cu in
1,995cc122cu in
Length
4,820mm190in
5,091mm200in
Width
1,855mm73in
1,902mm75in
Height
1,373mm54in
1,540mm61in
Wheelbase
2,780mm109in
3,070mm121in
Front track
1,558mm61in
1,615mm64in
Rear track
1,592mm63in
1,647mm65in
Ground clearance-
138mm5in
Trunk volume
300L
610L
Max trunk volume
350L
1,800L
Doors
2
5
Seats
4
5
Fuel tank
70L
66L
CO2 emissions-
129g/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 (E64) 645CiBMW 6 Series Gran Turismo (G32) 620dPowerTorque
  • BMW 6 Series Convertible (E64) 645Ci: Power / Torque
  • BMW 6 Series Gran Turismo (G32) 620d: Power / Torque
Dyno simulation data table
VehiclePeak power RPMPeak torque RPMMax engine speed
BMW6 Series Convertible (E64)645Ci6,100 rpm3,600 rpm6,350 rpm
BMW6 Series Gran Turismo (G32)620d4,000 rpm1,750-2,500 rpm4,250 rpm

Acceleration curve

Estimated speed over time for selected vehicles.

Acceleration and drag-race table
MetricBMW6 Series Convertible (E64)645CiBMW6 Series Gran Turismo (G32)620d
Acceleration checkpoints
0-60 mph
0-97 km/h
5.9 s
7.5 s
0-100 km/h
0-62 mph
6.2 s
7.9 s
0-200 km/h
0-124 mph
22.8 s
36.5 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Likely limited
Unrestricted
230 km/h143 mph
Restricted
220 km/h137 mph
Likely limited
Drag race simulation
60 ft
18 m
2.3 s
2.5 s
330 ft
101 m
6.2 s
6.8 s
1/8 mile
201 m
9.3 s
10.2 s
1000 ft
305 m
12.0 s
13.2 s
1/4 mile
402 m
14.3 s
15.7 s
Trap speed
1/4 mile
402 m
163 km/h
101 mph
146 km/h
91 mph

Power comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (E64)645Ci
333 hp
248 kW
BMW6 Series Gran Turismo (G32)620d
190 hp
142 kW

BMW 6 Series Convertible (E64) 645Ci has 143 hp more than BMW 6 Series Gran Turismo (G32) 620d.

The biggest power difference is between BMW 6 Series Gran Turismo (G32) 620d and BMW 6 Series Convertible (E64) 645Ci: 143 hp (107 kW).

Torque comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (E64)645Ci
450 Nm
332 lb-ft
BMW6 Series Gran Turismo (G32)620d
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 (E64)645Ci
1,820 kg
4,012 lb
BMW6 Series Gran Turismo (G32)620d
1,765 kg
3,891 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 (E64)645Ci
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
BMW6 Series Gran Turismo (G32)620d
Unrestricted
230 km/h143 mph
Restricted
220 km/h137 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 (E64)645Ci6.2 s
BMW6 Series Gran Turismo (G32)620d7.9 s

The biggest 0-100 km/h difference is between BMW 6 Series Convertible (E64) 645Ci and BMW 6 Series Gran Turismo (G32) 620d: 1.7 s.

Fuel consumption comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (E64)645Ci
11.5 L/100 km
20.5 mpg US
24.6 mpg UK
BMW6 Series Gran Turismo (G32)620d
4.9 L/100 km
48.0 mpg US
57.6 mpg UK

The biggest fuel consumption difference is between BMW 6 Series Gran Turismo (G32) 620d and BMW 6 Series Convertible (E64) 645Ci: 6.6 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 Convertible (E64)645Ci
183 hp/t
136 kW/t
5.5 kg/hp
BMW6 Series Gran Turismo (G32)620d
108 hp/t
80 kW/t
9.3 kg/hp

Estimated range comparison

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

Chart data table
VehicleValue
BMW6 Series Convertible (E64)645Ci
609 km
378 mi
BMW6 Series Gran Turismo (G32)620d
1,347 km
837 mi

Performance spider chart

Radar chart comparing normalized performance and fuel-consumption scores.

Chart data table
VehiclePowerAccelerationTop speed
BMW6 Series Convertible (E64)645Ci
333 hp
248 kW
6.2 s
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
BMW6 Series Gran Turismo (G32)620d
190 hp
142 kW
7.9 s
Unrestricted
230 km/h143 mph
Restricted
220 km/h137 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 (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
BMW6 Series Gran Turismo (G32)620d
Power
190 hp
142 kW
0-100 km/h7.9 s
Top speed
Unrestricted
230 km/h143 mph
Restricted
220 km/h137 mph
Doors/seats
5 doors
5 seats
Trunk
610 L
21.5 cu ft
Length
5,091 mm
200.4 in
Height
1,540 mm
60.6 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 (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
BMW6 Series Gran Turismo (G32)620d
Power
190 hp
142 kW
0-100 km/h7.9 s
Top speed
Unrestricted
230 km/h143 mph
Restricted
220 km/h137 mph
4.9 L/100 km
48.0 mpg US
57.6 mpg UK

BMW 6 Series Convertible (E64) 645Ci 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 (E64)645Ci
11.5 L/100 km
20.5 mpg US
24.6 mpg UK
6.2 s
BMW6 Series Gran Turismo (G32)620d
4.9 L/100 km
48.0 mpg US
57.6 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
VehiclePower-to-weight, hp/tFuel consumption, L/100 km
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
BMW6 Series Gran Turismo (G32)620d
108 hp/t
80 kW/t
9.3 kg/hp
4.9 L/100 km
48.0 mpg US
57.6 mpg UK

Detailed score breakdown

Detailed score breakdown
VehicleBMW6 Series Convertible (E64)645CiBMW6 Series Gran Turismo (G32)620d
Power
333 hp
248 kW
190 hp
142 kW
Torque
450 Nm
332 lb-ft
400 Nm
295 lb-ft
Acceleration
6.2 s
7.9 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Unrestricted
230 km/h143 mph
Restricted
220 km/h137 mph
Lightness
1,820 kg
4,012 lb
1,765 kg
3,891 lb
Fuel consumption
11.5 L/100 km
20.5 mpg US
24.6 mpg UK
4.9 L/100 km
48.0 mpg US
57.6 mpg UK
Practicality
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
Doors/seats
5 doors
5 seats
Trunk
610 L
21.5 cu ft
Length
5,091 mm
200.4 in
Height
1,540 mm
60.6 in
Range score
609 km
378 mi
1,347 km
837 mi
CO2 score
-
129 g/km
Trunk score
300 L
10.6 cu ft
610 L
21.5 cu ft
Power-to-weight score
183 hp/t
136 kW/t
5.5 kg/hp
108 hp/t
80 kW/t
9.3 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 6 Series Convertible (E64) 645CiBMW 6 Series Gran Turismo (G32) 620d
Consumption11.5 L/100 km20.5 mpg US24.6 mpg UK4.9 L/100 km48 mpg US57.6 mpg UK
Cost / 100 km20.13 LC100 km8.58 LC100 km
Cost / 100 mi32.39 LC100 mi13.80 LC100 mi
Annual fuel used1,725 L456 US gal379 UK gal735 L194 US gal162 UK gal
Annual fuel cost3,019 LC/year1,286 LC/year

Head-to-head comparisons

BMW 6 Series Convertible (E64) 645Ci

  • Has 143 hp more
  • Has 50 Nm more
  • Is 1.7 s quicker from 0-100 km/h
  • Has 30 km/h (19 mph) higher top speed
  • Has 75 hp/t better power-to-weight

Pros

  • Quickest 0-100 km/h in this comparison
  • Highest top speed
  • Most powerful
  • Highest torque
  • Best power-to-weight ratio

Cons

  • Highest combined fuel consumption
  • Heaviest
  • Smallest trunk

BMW 6 Series Gran Turismo (G32) 620d

  • Is 55 kg lighter
  • Uses 6.6 L/100 km less fuel
  • Has 738 km (459 mi) more estimated range
  • Has 310 L more trunk volume

Pros

  • Lightest
  • Lowest combined fuel consumption
  • Best estimated range
  • 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 (E64) 645Ci
BMW 6 Series Gran Turismo (G32) 620d
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