2004 Audi A6 vs. 2003 BMW 645
To start off, 2004 Audi A6 is newer by 1 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 (310 HP @ 6000 RPM) has 63 more horse power than 2004 Audi A6. (247 HP @ 6300 RPM) In normal driving conditions, 2003 BMW 645 should accelerate faster than 2004 Audi A6. With that said, vehicle weight also plays an important factor in acceleration. 2004 Audi A6 weights approximately 107 kg more than 2003 BMW 645.
Because 2004 Audi A6 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, 2004 Audi A6 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 110 more torque (in Nm) than 2004 Audi A6. (340 Nm @ 1800 RPM). This means 2003 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 2004 Audi A6. 2003 BMW 645 has automatic transmission and 2004 Audi A6 has manual transmission. 2004 Audi A6 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:
| 2004 Audi A6 | 2003 BMW 645 | |
| Make | Audi | BMW |
| Model | A6 | 645 |
| Year Released | 2004 | 2003 |
| Body Type | Station Wagon | Coupe |
| Engine Position | Front | Front |
| Engine Size | 2671 cc | 4398 cc |
| Engine Cylinders | 6 cylinders | 8 cylinders |
| Engine Type | V | V |
| Valves per Cylinder | 5 valves | 4 valves |
| Horse Power | 247 HP | 310 HP |
| Engine RPM | 6300 RPM | 6000 RPM |
| Torque | 340 Nm | 450 Nm |
| Torque RPM | 1800 RPM | 3600 RPM |
| Engine Bore Size | 81 mm | 92 mm |
| Engine Stroke Size | 86 mm | 82.7 mm |
| Drive Type | 4WD | Rear |
| Transmission Type | Manual | Automatic |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 5 doors | 2 doors |
| Vehicle Weight | 1805 kg | 1698 kg |
| Vehicle Length | 4800 mm | 4830 mm |
| Vehicle Width | 1860 mm | 1860 mm |
| Vehicle Height | 1560 mm | 1380 mm |
| Wheelbase Size | 2770 mm | 2790 mm |
| Fuel Tank Capacity | 70 L | 70 L |
