Car comparison

Alpina Roadster S 3.3 i 24VvsBMW 6 Series Convertible (E64) 645Ci

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

New comparison

Alpina Roadster S

3.3 i 24V

300 hp3346 ccGasolineRWDManualNaturally aspiratedCabriolet / convertible2003-2006

BMW 6 Series Convertible (E64)

645Ci

333 hp4398 ccGasolineRWDManualNaturally aspiratedCabriolet / convertible2003-2005

Comparison overview

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

Alpina Roadster S 3.3 i 24V

Quickest 0-100 km/h
5.3 s
Fastest top speed
265 km/h
165 mph
Lightest
1,320 kg
2,910 lb
Best power-to-weight
227 hp/t
169 kW/t
4.4 kg/hp
Lowest city consumption
15.0 L/100 km
15.7 mpg US
18.8 mpg UK
Lowest highway consumption
7.0 L/100 km
33.6 mpg US
40.4 mpg UK
Best performance score
67/100

BMW 6 Series Convertible (E64) 645Ci

Most powerful
333 hp
248 kW
Highest torque
450 Nm
332 lb-ft
Largest trunk
300 L
Best overall score
59/100
Best economy score
72/100
Best practicality score
45/100

Specification comparison

Specification comparison
Model	AlpinaRoadster S3.3 i 24V	BMW6 Series Convertible (E64)645Ci
Power	300hp224kW	333hp248kW
Torque	362Nm267lb-ft	450Nm332lb-ft
Curb weight	1,320kg2,910lb	1,815kg4,001lb
Gross weight	1,620kg3,571lb	2,215kg4,883lb
Top speed	265 km/h 165 mph	Unrestricted 260 km/h162 mph Restricted 250 km/h155 mph Calculated
To 99% top speed	66.7s99% target: 262 km/h / 163 mph Calculated	87.6s99% target: 257 km/h / 160 mph Calculated
0-100 km/h	5.3s	6.1s
0-200 km/h	17.8s Calculated	22.6s Calculated
0-60 mph	5.0s Calculated	5.8s Calculated
Fuel consumption	-	12.9L/100 km18.2mpg US21.9mpg UK
Fuel consumption city	15L/100 km15.7mpg US18.8mpg UK	18.5L/100 km12.7mpg US15.3mpg UK
Fuel consumption highway	7L/100 km33.6mpg US40.4mpg UK	9.6L/100 km24.5mpg US29.4mpg UK
Quarter mile	13.4s Calculated	14.2s Calculated
Power-to-weight	227hp/t169kW/t103hp/1000 lb Calculated	183hp/t137kW/t83hp/1000 lb Calculated
Torque-to-weight	274Nm/t183lb-ft/ton Calculated	248Nm/t166lb-ft/ton Calculated
Estimated range	-	543km337mi Calculated
Displacement	3,346cc204cu in	4,398cc268cu in
Length	4,090mm161in	4,820mm190in
Width	1,780mm70in	1,855mm73in
Height	1,300mm51in	1,373mm54in
Wheelbase	2,500mm98in	2,780mm109in
Front track	1,470mm58in	1,558mm61in
Rear track	1,520mm60in	1,592mm63in
Trunk volume	240L	300L
Max trunk volume	260L	350L
Doors	2	2
Seats	2	4
Fuel tank	55L	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.

Alpina Roadster S 3.3 i 24VBMW 6 Series Convertible (E64) 645CiPowerTorque

Dyno simulation data table
Vehicle	Peak power RPM	Peak torque RPM	Max engine speed
AlpinaRoadster S3.3 i 24V	6,300 rpm	4,800 rpm	6,550 rpm
BMW6 Series Convertible (E64)645Ci	6,100 rpm	3,600 rpm	6,350 rpm

Acceleration curve

Estimated speed over time for selected vehicles.

Acceleration and drag-race table
Metric	AlpinaRoadster S3.3 i 24V	BMW6 Series Convertible (E64)645Ci
	Acceleration checkpoints
0-60 mph 0-97 km/h	5.0 s	5.8 s
0-100 km/h 0-62 mph	5.3 s	6.1 s
0-200 km/h 0-124 mph	17.8 s	22.6 s
Top speed	265 km/h 165 mph	Unrestricted 260 km/h162 mph Restricted 250 km/h155 mph Likely limited
	Drag race simulation
60 ft 18 m	2.3 s	2.3 s
330 ft 101 m	5.9 s	6.2 s
1/8 mile 201 m	8.8 s	9.3 s
1000 ft 305 m	11.3 s	12.0 s
1/4 mile 402 m	13.4 s	14.2 s
Trap speed 1/4 mile 402 m	176 km/h 109 mph	163 km/h 102 mph

Power comparison

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

Chart data table
Vehicle	Value
AlpinaRoadster S3.3 i 24V	300 hp 224 kW
BMW6 Series Convertible (E64)645Ci	333 hp 248 kW

BMW 6 Series Convertible (E64) 645Ci has 33 hp more than Alpina Roadster S 3.3 i 24V.

The biggest power difference is between Alpina Roadster S 3.3 i 24V and BMW 6 Series Convertible (E64) 645Ci: 33 hp (25 kW).

Torque comparison

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

Chart data table
Vehicle	Value
AlpinaRoadster S3.3 i 24V	362 Nm 267 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
Vehicle	Value
AlpinaRoadster S3.3 i 24V	1,320 kg 2,910 lb
BMW6 Series Convertible (E64)645Ci	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
Vehicle	Value
AlpinaRoadster S3.3 i 24V	265 km/h 165 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
Vehicle	Value
AlpinaRoadster S3.3 i 24V	5.3 s
BMW6 Series Convertible (E64)645Ci	6.1 s

Although BMW 6 Series Convertible (E64) 645Ci has more power, Alpina Roadster S 3.3 i 24V is quicker from 0-100 km/h.

The biggest 0-100 km/h difference is between Alpina Roadster S 3.3 i 24V and BMW 6 Series Convertible (E64) 645Ci: 0.8 s.

Power-to-weight comparison

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

Chart data table
Vehicle	Value
AlpinaRoadster S3.3 i 24V	227 hp/t 169 kW/t 4.4 kg/hp
BMW6 Series Convertible (E64)645Ci	183 hp/t 137 kW/t 5.5 kg/hp

Performance spider chart

Radar chart comparing normalized performance and fuel-consumption scores.

Chart data table
Vehicle	Power	Acceleration	Top speed
AlpinaRoadster S3.3 i 24V	300 hp 224 kW	5.3 s	265 km/h 165 mph
BMW6 Series Convertible (E64)645Ci	333 hp 248 kW	6.1 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.

Vehicle

Performance score

Practicality score

AlpinaRoadster S3.3 i 24V

Power	300 hp 224 kW
0-100 km/h	5.3 s
Top speed 265 km/h 165 mph

Doors/seats	2 doors 2 seats
Trunk	240 L 8.5 cu ft
Length	4,090 mm 161.0 in
Height	1,300 mm 51.2 in

BMW6 Series Convertible (E64)645Ci

Power	333 hp 248 kW
0-100 km/h	6.1 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

Detailed score breakdown

Vehicle

AlpinaRoadster S3.3 i 24V

BMW6 Series Convertible (E64)645Ci

Power

300 hp

224 kW

333 hp

248 kW

Torque

362 Nm

267 lb-ft

450 Nm

332 lb-ft

Acceleration

5.3 s

6.1 s

Top speed

265 km/h

165 mph

Unrestricted

260 km/h162 mph

Restricted

250 km/h155 mph

Lightness

1,320 kg

2,910 lb

1,815 kg

4,001 lb

Fuel consumption

12.9 L/100 km

18.2 mpg US

21.9 mpg UK

Practicality

Doors/seats	2 doors 2 seats
Trunk	240 L 8.5 cu ft
Length	4,090 mm 161.0 in
Height	1,300 mm 51.2 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

543 km

337 mi

Trunk score

240 L

8.5 cu ft

300 L

10.6 cu ft

Power-to-weight score

227 hp/t

169 kW/t

4.4 kg/hp

183 hp/t

137 kW/t

5.5 kg/hp

Overall

Fixed score

Fuel cost and annual usage

Estimate running costs from combined consumption, your annual distance, and the fuel price in your local currency.

Average annual distanceDistance unitFuel price in your local currencyPrice unit

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
Vehicle	BMW 6 Series Convertible (E64) 645Ci
Consumption	12.9 L/100 km18.2 mpg US21.9 mpg UK
Cost / 100 km	22.58 LC100 km
Cost / 100 mi	36.33 LC100 mi
Annual fuel used	1,935 L511 US gal426 UK gal
Annual fuel cost	3,386 LC/year