Car comparison

BMW 6 Series Convertible (E64) 645CivsBMW 6 Series (E63) 630i

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 (E63)

630i

258 hp2996 ccGasolineRWDManualNaturally aspiratedCoupe2004-2007

Comparison overview

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

Best choices

BMW 6 Series (E63) 630i

  • Lightest
    1,490 kg
    3,285 lb
  • Lowest combined fuel consumption
    9.0 L/100 km
    26.1 mpg US
    31.4 mpg UK
  • Lowest city consumption
    13.1 L/100 km
    18.0 mpg US
    21.6 mpg UK
  • Lowest highway consumption
    6.7 L/100 km
    35.1 mpg US
    42.2 mpg UK
  • Best estimated range
    778 km
    483 mi
  • Largest trunk
    450 L
  • Best economy score
    83/100
  • Best practicality score
    53/100

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 overall score
    59/100
  • Best performance score
    65/100

Specification comparison

Specification comparison
ModelBMW6 Series Convertible (E64)645CiBMW6 Series (E63)630i
Power
333hp248kW
258hp192kW
Torque
450Nm332lb-ft
300Nm221lb-ft
Curb weight
1,820kg4,012lb
1,490kg3,285lb
Gross weight
2,220kg4,894lb
1,940kg4,277lb
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
87.8s99% target: 257 km/h / 160 mph
Calculated
89.2s99% target: 257 km/h / 160 mph
Calculated
0-100 km/h
6.2s
6.5s
0-200 km/h
22.8s
Calculated
23.5s
Calculated
0-60 mph
5.9s
Calculated
6.2s
Calculated
Fuel consumption
11.5L/100 km20.5mpg US24.6mpg UK
9L/100 km26.1mpg US31.4mpg UK
Fuel consumption city
16.8L/100 km14mpg US16.8mpg UK
13.1L/100 km18mpg US21.6mpg UK
Fuel consumption highway
8.5L/100 km27.7mpg US33.2mpg UK
6.7L/100 km35.1mpg US42.2mpg UK
Quarter mile
14.3s
Calculated
14.5s
Calculated
Power-to-weight
183hp/t136kW/t83hp/1000 lb
Calculated
173hp/t129kW/t79hp/1000 lb
Calculated
Torque-to-weight
247Nm/t165lb-ft/ton
Calculated
201Nm/t135lb-ft/ton
Calculated
Estimated range
609km378mi
Calculated
778km483mi
Calculated
Displacement
4,398cc268cu in
2,996cc183cu in
Length
4,820mm190in
4,820mm190in
Width
1,855mm73in
1,855mm73in
Height
1,373mm54in
1,373mm54in
Wheelbase
2,780mm109in
2,780mm109in
Front track
1,558mm61in
1,558mm61in
Rear track
1,592mm63in
1,596mm63in
Trunk volume
300L
450L
Max trunk volume
350L
-
Doors
2
2
Seats
4
4
Fuel tank
70L
70L

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 (E63) 630iPowerTorque
  • BMW 6 Series Convertible (E64) 645Ci: Power / Torque
  • BMW 6 Series (E63) 630i: 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 (E63)630i6,600 rpm2,500 rpm6,850 rpm

Acceleration curve

Estimated speed over time for selected vehicles.

Acceleration and drag-race table
MetricBMW6 Series Convertible (E64)645CiBMW6 Series (E63)630i
Acceleration checkpoints
0-60 mph
0-97 km/h
5.9 s
6.2 s
0-100 km/h
0-62 mph
6.2 s
6.5 s
0-200 km/h
0-124 mph
22.8 s
23.5 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
2.4 s
2.4 s
330 ft
101 m
6.2 s
6.4 s
1/8 mile
201 m
9.3 s
9.5 s
1000 ft
305 m
12.0 s
12.3 s
1/4 mile
402 m
14.3 s
14.5 s
Trap speed
1/4 mile
402 m
163 km/h
101 mph
161 km/h
100 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 (E63)630i
258 hp
192 kW

BMW 6 Series Convertible (E64) 645Ci has 75 hp more than BMW 6 Series (E63) 630i.

The biggest power difference is between BMW 6 Series (E63) 630i and BMW 6 Series Convertible (E64) 645Ci: 75 hp (56 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 (E63)630i
300 Nm
221 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 (E63)630i
1,490 kg
3,285 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 (E63)630i
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 Convertible (E64)645Ci6.2 s
BMW6 Series (E63)630i6.5 s

The biggest 0-100 km/h difference is between BMW 6 Series Convertible (E64) 645Ci and BMW 6 Series (E63) 630i: 0.3 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 (E63)630i
9.0 L/100 km
26.1 mpg US
31.4 mpg UK

The biggest fuel consumption difference is between BMW 6 Series (E63) 630i and BMW 6 Series Convertible (E64) 645Ci: 2.5 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
BMW6 Series Convertible (E64)645Ci
183 hp/t
136 kW/t
5.5 kg/hp
BMW6 Series (E63)630i
173 hp/t
129 kW/t
5.8 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 (E63)630i
778 km
483 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 (E63)630i
258 hp
192 kW
6.5 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 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 (E63)630i
Power
258 hp
192 kW
0-100 km/h6.5 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Doors/seats
2 doors
4 seats
Trunk
450 L
15.9 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 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 (E63)630i
Power
258 hp
192 kW
0-100 km/h6.5 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
9.0 L/100 km
26.1 mpg US
31.4 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 (E63)630i
9.0 L/100 km
26.1 mpg US
31.4 mpg UK
6.5 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 (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 (E63)630i
173 hp/t
129 kW/t
5.8 kg/hp
9.0 L/100 km
26.1 mpg US
31.4 mpg UK

Detailed score breakdown

Detailed score breakdown
VehicleBMW6 Series Convertible (E64)645CiBMW6 Series (E63)630i
Power
333 hp
248 kW
258 hp
192 kW
Torque
450 Nm
332 lb-ft
300 Nm
221 lb-ft
Acceleration
6.2 s
6.5 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Lightness
1,820 kg
4,012 lb
1,490 kg
3,285 lb
Fuel consumption
11.5 L/100 km
20.5 mpg US
24.6 mpg UK
9.0 L/100 km
26.1 mpg US
31.4 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
2 doors
4 seats
Trunk
450 L
15.9 cu ft
Length
4,820 mm
189.8 in
Height
1,373 mm
54.1 in
Range score
609 km
378 mi
778 km
483 mi
Trunk score
300 L
10.6 cu ft
450 L
15.9 cu ft
Power-to-weight score
183 hp/t
136 kW/t
5.5 kg/hp
173 hp/t
129 kW/t
5.8 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 (E63) 630i
Consumption11.5 L/100 km20.5 mpg US24.6 mpg UK9 L/100 km26.1 mpg US31.4 mpg UK
Cost / 100 km20.13 LC100 km15.75 LC100 km
Cost / 100 mi32.39 LC100 mi25.35 LC100 mi
Annual fuel used1,725 L456 US gal379 UK gal1,350 L357 US gal297 UK gal
Annual fuel cost3,019 LC/year2,363 LC/year

Head-to-head comparisons

BMW 6 Series Convertible (E64) 645Ci

  • Has 75 hp more
  • Has 150 Nm more
  • Is 0.3 s quicker from 0-100 km/h
  • Has 10 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 (E63) 630i

  • Is 330 kg lighter
  • Uses 2.5 L/100 km less fuel
  • Has 169 km (105 mi) more estimated range
  • Has 150 L more trunk volume

Pros

  • Lightest
  • Lowest combined fuel consumption
  • Best estimated range
  • Largest trunk

Cons

  • Slowest 0-100 km/h
  • Lowest power

Choose cars to compare

Brand
Model
Generation
Engine or modification
BMW 6 Series Convertible (E64) 645Ci
BMW 6 Series (E63) 630i
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