2005 Audi A6 vs. 2003 BMW 645
To start off, 2005 Audi A6 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 (321 HP @ 6100 RPM) has 160 more horse power than 2005 Audi A6. (161 HP @ 4000 RPM) In normal driving conditions, 2003 BMW 645 should accelerate faster than 2005 Audi A6. With that said, vehicle weight also plays an important factor in acceleration. 2003 BMW 645 weights approximately 250 kg more than 2005 Audi A6. So despite on having greater horse power, its additional weight may have an impact towards its acceleration in comparison.
Because 2003 BMW 645 is rear wheel drive (RWD), it offers better handling in dry conditions; in addition, if you are looking to drift, it will be much easier to do with 2003 BMW 645. However, in wet, icy, snow, or gravel driving conditions, 2005 Audi A6, being front wheel drive (FWD), will offer much better control with better grip. 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 A6. (310 Nm @ 1400 RPM). This means 2003 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 2005 Audi A6.
Compare all specifications:
| 2005 Audi A6 | 2003 BMW 645 | |
| Make | Audi | BMW |
| Model | A6 | 645 |
| Year Released | 2005 | 2003 |
| Body Type | Station Wagon | Convertible |
| Engine Position | Front | Front |
| Engine Size | 2496 cc | 4398 cc |
| Valves per Cylinder | 4 valves | 4 valves |
| Horse Power | 161 HP | 321 HP |
| Engine RPM | 4000 RPM | 6100 RPM |
| Torque | 310 Nm | 450 Nm |
| Torque RPM | 1400 RPM | 3600 RPM |
| Engine Compression Ratio | 19.5:1 | 10.5:1 |
| Top Speed | 210 km/hour | 250 km/hour |
| Acceleration 0-100mph | 9.5 seconds | 6.2 seconds |
| Drive Type | Front | Rear |
| Transmission Type | Automatic | Automatic |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 5 doors | 2 doors |
| Vehicle Weight | 1645 kg | 1895 kg |
| Wheelbase Size | 2850 mm | 2790 mm |
| Fuel Consumption Overall | 6.9 L/100km | 11.5 L/100km |
| Fuel Tank Capacity | 70 L | 70 L |
