2003 BMW 645 vs. 2003 BMW 520
To start off, both 2003 BMW 645 and 2003 BMW 520 were released in the same year (2003). Therefore the support and the availability on parts for both vehicles should be relatively similar. At 4,398 cc (8 cylinders), 2003 BMW 645 is equipped with a bigger engine. In terms of performance, 2003 BMW 645 (321 HP @ 6100 RPM) has 154 more horse power than 2003 BMW 520. (167 HP @ 5800 RPM). In normal driving conditions, 2003 BMW 645 should accelerate faster than 2003 BMW 520. With that said, vehicle weight also plays an important factor in acceleration. 2003 BMW 645 weights approximately 335 kg more than 2003 BMW 520. So despite on having greater horse power, its additional weight may have an impact towards its acceleration in comparison.
Both vehicles are rear wheel drive (RWD) - it offers better handling in dry conditions; in addition, if you are looking to drift, both vehicles do the job better than front wheel drive vehicles. With that said, do keep in mind that many other factors such as speed and the wear on your tires can also have significant impact on traction and control. Let's talk about torque, 2003 BMW 645 (450 Nm @ 3600 RPM) has 240 more torque (in Nm) than 2003 BMW 520. (210 Nm @ 3500 RPM). This means 2003 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 2003 BMW 520. 2003 BMW 645 has automatic transmission and 2003 BMW 520 has manual transmission. 2003 BMW 520 will offer better control over acceleration and deceleration in addition to better fuel efficiency overall. 2003 BMW 645 will be easier to drive especially in heavy traffic.
Compare all specifications:
| 2003 BMW 645 | 2003 BMW 520 | |
| Make | BMW | BMW |
| Model | 645 | 520 |
| Year Released | 2003 | 2003 |
| Body Type | Convertible | Sedan |
| Engine Position | Front | Front |
| Engine Size | 4398 cc | 2171 cc |
| Engine Cylinders | 8 cylinders | 6 cylinders |
| Engine Type | V | in-line |
| Valves per Cylinder | 4 valves | 4 valves |
| Horse Power | 321 HP | 167 HP |
| Engine RPM | 6100 RPM | 5800 RPM |
| Torque | 450 Nm | 210 Nm |
| Torque RPM | 3600 RPM | 3500 RPM |
| Engine Bore Size | 92 mm | 80 mm |
| Engine Stroke Size | 82.7 mm | 72 mm |
| Engine Compression Ratio | 10.5:1 | 10.8:1 |
| Top Speed | 250 km/hour | 230 km/hour |
| Acceleration 0-100mph | 6.2 seconds | 9.3 seconds |
| Drive Type | Rear | Rear |
| Transmission Type | Automatic | Manual |
| Number of Seats | 4 seats | 5 seats |
| Number of Doors | 2 doors | 4 doors |
| Vehicle Weight | 1895 kg | 1560 kg |
| Vehicle Length | 4830 mm | 4850 mm |
| Vehicle Width | 1860 mm | 1850 mm |
| Vehicle Height | 1380 mm | 1470 mm |
| Wheelbase Size | 2790 mm | 3000 mm |
| Fuel Consumption Highway | 8.5 L/100km | 6.8 L/100km |
| Fuel Consumption City | 16.8 L/100km | 13 L/100km |
| Fuel Consumption Overall | 11.5 L/100km | 9 L/100km |
| Fuel Tank Capacity | 70 L | 70 L |
