2005 Audi A4 vs. 2003 BMW 645
To start off, 2005 Audi A4 is newer by 2 year(s). Which means there will be less support and parts availability for 2003 BMW 645. In addition, the cost of maintenance, including insurance, on 2003 BMW 645 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 197 more horse power than 2005 Audi A4. (128 HP @ 4000 RPM) In normal driving conditions, 2003 BMW 645 should accelerate faster than 2005 Audi A4. With that said, vehicle weight also plays an important factor in acceleration. 2003 BMW 645 weights approximately 205 kg more than 2005 Audi A4. So despite on having greater horse power, its additional weight may have an impact towards its acceleration in comparison.
Because 2005 Audi A4 is four wheel drive (4WD), it will have significant more traction and grip than 2003 BMW 645. In wet, icy, snow, or gravel driving conditions, 2005 Audi A4 will offer significantly more control. 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 140 more torque (in Nm) than 2005 Audi A4. (310 Nm @ 1900 RPM). This means 2003 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 2005 Audi A4.
Compare all specifications:
| 2005 Audi A4 | 2003 BMW 645 | |
| Make | Audi | BMW |
| Model | A4 | 645 |
| Year Released | 2005 | 2003 |
| Body Type | Sedan | Coupe |
| Engine Position | Front | Front |
| Engine Size | 1896 cc | 4398 cc |
| Engine Cylinders | 4 cylinders | 8 cylinders |
| Engine Type | in-line | V |
| Valves per Cylinder | 2 valves | 4 valves |
| Horse Power | 128 HP | 325 HP |
| Engine RPM | 4000 RPM | 6100 RPM |
| Torque | 310 Nm | 450 Nm |
| Torque RPM | 1900 RPM | 3600 RPM |
| Engine Bore Size | 79.5 mm | 92 mm |
| Engine Stroke Size | 95.5 mm | 82.7 mm |
| Engine Compression Ratio | 19.0:1 | 10.5:1 |
| Top Speed | 205 km/hour | 250 km/hour |
| Acceleration 0-100mph | 10.1 seconds | 5.9 seconds |
| Drive Type | 4WD | Rear |
| Transmission Type | Manual | Manual |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 4 doors | 2 doors |
| Vehicle Weight | 1485 kg | 1690 kg |
| Vehicle Length | 4550 mm | 4830 mm |
| Vehicle Width | 1780 mm | 1860 mm |
| Vehicle Height | 1430 mm | 1380 mm |
| Wheelbase Size | 2580 mm | 2890 mm |
| Fuel Consumption Overall | 6.6 L/100km | 11.7 L/100km |
| Fuel Tank Capacity | 66 L | 70 L |
