2003 BMW M3 vs. 2003 BMW 645
To start off, both 2003 BMW M3 and 2003 BMW 645 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 M3 (342 HP @ 7900 RPM) has 21 more horse power than 2003 BMW 645. (321 HP @ 6100 RPM). In normal driving conditions, 2003 BMW M3 should accelerate faster than 2003 BMW 645. With that said, vehicle weight also plays an important factor in acceleration. 2003 BMW 645 weights approximately 510 kg more than 2003 BMW M3.
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 100 more torque (in Nm) than 2003 BMW M3. (350 Nm @ 4900 RPM). This means 2003 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 2003 BMW M3. 2003 BMW 645 has automatic transmission and 2003 BMW M3 has manual transmission. 2003 BMW M3 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 M3 | 2003 BMW 645 | |
| Make | BMW | BMW |
| Model | M3 | 645 |
| Year Released | 2003 | 2003 |
| Body Type | Coupe | Convertible |
| Engine Position | Front | Front |
| Engine Size | 3168 cc | 4398 cc |
| Engine Cylinders | 6 cylinders | 8 cylinders |
| Engine Type | in-line | V |
| Valves per Cylinder | 4 valves | 4 valves |
| Horse Power | 342 HP | 321 HP |
| Engine RPM | 7900 RPM | 6100 RPM |
| Torque | 350 Nm | 450 Nm |
| Torque RPM | 4900 RPM | 3600 RPM |
| Engine Bore Size | 87 mm | 92 mm |
| Engine Stroke Size | 91 mm | 82.7 mm |
| Engine Compression Ratio | 11.5:1 | 10.5:1 |
| Top Speed | 259 km/hour | 250 km/hour |
| Acceleration 0-100mph | 4.9 seconds | 6.2 seconds |
| Drive Type | Rear | Rear |
| Transmission Type | Manual | Automatic |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 2 doors | 2 doors |
| Vehicle Weight | 1385 kg | 1895 kg |
| Vehicle Length | 4500 mm | 4830 mm |
| Vehicle Width | 1790 mm | 1860 mm |
| Vehicle Height | 1370 mm | 1380 mm |
| Wheelbase Size | 2730 mm | 2790 mm |
| Fuel Consumption | 8.4 L/100km | 8.5 L/100km |
| Fuel Consumption City | 17.8 L/100km | 16.8 L/100km |
| Fuel Consumption Overall | 11.4 L/100km | 11.5 L/100km |
| Fuel Tank Capacity | 63 L | 70 L |
