2008 Audi A6 vs. 2004 BMW 645
To start off, 2008 Audi A6 is newer by 4 year(s). Which means there will be less support and parts availability for 2004 BMW 645. In addition, the cost of maintenance, including insurance, on 2004 BMW 645 would be higher. At 4,392 cc (8 cylinders), 2004 BMW 645 is equipped with a bigger engine. In terms of performance, 2004 BMW 645 (322 HP @ 7400 RPM) has 92 more horse power than 2008 Audi A6. (230 HP @ 4000 RPM) In normal driving conditions, 2004 BMW 645 should accelerate faster than 2008 Audi A6. With that said, vehicle weight also plays an important factor in acceleration. 2008 Audi A6 weights approximately 50 kg more than 2004 BMW 645.
Because 2004 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 2004 BMW 645. However, in wet, icy, snow, or gravel driving conditions, 2008 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, 2008 Audi A6 (450 Nm) has 3 more torque (in Nm) than 2004 BMW 645. (447 Nm). This means 2008 Audi A6 will have an easier job in driving up hills or pulling heavy equipment than 2004 BMW 645.
Compare all specifications:
| 2008 Audi A6 | 2004 BMW 645 | |
| Make | Audi | BMW |
| Model | A6 | 645 |
| Year Released | 2008 | 2004 |
| Body Type | Sedan | Coupe |
| Engine Position | Front | Front |
| Engine Size | 2965 cc | 4392 cc |
| Engine Cylinders | 6 cylinders | 8 cylinders |
| Engine Type | V | V |
| Valves per Cylinder | 4 valves | 4 valves |
| Horse Power | 230 HP | 322 HP |
| Engine RPM | 4000 RPM | 7400 RPM |
| Torque | 450 Nm | 447 Nm |
| Engine Bore Size | 83 mm | 92 mm |
| Engine Stroke Size | 91.4 mm | 83 mm |
| Engine Compression Ratio | 17.0:1 | 10.5:1 |
| Drive Type | Front | Rear |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 4 doors | 2 doors |
| Vehicle Weight | 1765 kg | 1715 kg |
| Vehicle Length | 4920 mm | 4840 mm |
| Vehicle Width | 1860 mm | 1860 mm |
| Vehicle Height | 1470 mm | 1380 mm |
| Wheelbase Size | 2850 mm | 2790 mm |
| Fuel Consumption Overall | 6.3 L/100km | 11.8 L/100km |
| Fuel Tank Capacity | 80 L | 70 L |
