1991 BMW 320 vs. 2003 BMW 645
To start off, 2003 BMW 645 is newer by 12 year(s). Which means there will be less support and parts availability for 1991 BMW 320. In addition, the cost of maintenance, including insurance, on 1991 BMW 320 would be higher. At 4,398 cc (8 cylinders), 2003 BMW 645 is equipped with a bigger engine. In terms of performance, 2003 BMW 645 (325 HP @ 6100 RPM) has 176 more horse power than 1991 BMW 320. (149 HP @ 5900 RPM) In normal driving conditions, 2003 BMW 645 should accelerate faster than 1991 BMW 320. With that said, vehicle weight also plays an important factor in acceleration. 2003 BMW 645 weights approximately 420 kg more than 1991 BMW 320. 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 260 more torque (in Nm) than 1991 BMW 320. (190 Nm @ 4200 RPM). This means 2003 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 1991 BMW 320.
Compare all specifications:
| 1991 BMW 320 | 2003 BMW 645 | |
| Make | BMW | BMW |
| Model | 320 | 645 |
| Year Released | 1991 | 2003 |
| Body Type | Sedan | Coupe |
| Engine Position | Front | Front |
| Engine Size | 1991 cc | 4398 cc |
| Engine Cylinders | 6 cylinders | 8 cylinders |
| Engine Type | in-line | V |
| Horse Power | 149 HP | 325 HP |
| Engine RPM | 5900 RPM | 6100 RPM |
| Torque | 190 Nm | 450 Nm |
| Torque RPM | 4200 RPM | 3600 RPM |
| Engine Bore Size | 80 mm | 92 mm |
| Engine Stroke Size | 66 mm | 82.7 mm |
| Engine Compression Ratio | 11.0:1 | 10.5:1 |
| Top Speed | 214 km/hour | 250 km/hour |
| Acceleration 0-100mph | 9.8 seconds | 5.9 seconds |
| Drive Type | Rear | Rear |
| Transmission Type | Manual | Manual |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 4 doors | 2 doors |
| Vehicle Weight | 1270 kg | 1690 kg |
| Vehicle Length | 4450 mm | 4830 mm |
| Vehicle Width | 1710 mm | 1860 mm |
| Vehicle Height | 1400 mm | 1380 mm |
| Wheelbase Size | 2710 mm | 2890 mm |
| Fuel Tank Capacity | 65 L | 70 L |
