2008 Audi A8 vs. 2005 BMW 645
To start off, 2008 Audi A8 is newer by 3 year(s). Which means there will be less support and parts availability for 2005 BMW 645. In addition, the cost of maintenance, including insurance, on 2005 BMW 645 would be higher. At 4,392 cc (8 cylinders), 2005 BMW 645 is equipped with a bigger engine. In terms of performance, 2005 BMW 645 (326 HP @ 6100 RPM) has 55 more horse power than 2008 Audi A8. (271 HP @ 3750 RPM) In normal driving conditions, 2005 BMW 645 should accelerate faster than 2008 Audi A8. With that said, vehicle weight also plays an important factor in acceleration. 2008 Audi A8 weights approximately 49 kg more than 2005 BMW 645.
Because 2008 Audi A8 is four wheel drive (4WD), it will have significant more traction and grip than 2005 BMW 645. In wet, icy, snow, or gravel driving conditions, 2008 Audi A8 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, 2008 Audi A8 (650 Nm @ 1800 RPM) has 203 more torque (in Nm) than 2005 BMW 645. (447 Nm @ 3600 RPM). This means 2008 Audi A8 will have an easier job in driving up hills or pulling heavy equipment than 2005 BMW 645. 2008 Audi A8 has automatic transmission and 2005 BMW 645 has manual transmission. 2005 BMW 645 will offer better control over acceleration and deceleration in addition to better fuel efficiency overall. 2008 Audi A8 will be easier to drive especially in heavy traffic.
Compare all specifications:
| 2008 Audi A8 | 2005 BMW 645 | |
| Make | Audi | BMW |
| Model | A8 | 645 |
| Year Released | 2008 | 2005 |
| Body Type | Sedan | Convertible |
| Engine Position | Front | Front |
| Engine Size | 3936 cc | 4392 cc |
| Engine Cylinders | 8 cylinders | 8 cylinders |
| Engine Type | V | V |
| Valves per Cylinder | 4 valves | 4 valves |
| Horse Power | 271 HP | 326 HP |
| Engine RPM | 3750 RPM | 6100 RPM |
| Torque | 650 Nm | 447 Nm |
| Torque RPM | 1800 RPM | 3600 RPM |
| Engine Bore Size | 81 mm | 92 mm |
| Engine Stroke Size | 95.5 mm | 83 mm |
| Engine Compression Ratio | 18.0:1 | 10.5:1 |
| Fuel Type | Diesel | Gasoline - Premium |
| Top Speed | 250 km/hour | 250 km/hour |
| Acceleration 0-100mph | 6.8 seconds | 6.1 seconds |
| Drive Type | 4WD | Rear |
| Transmission Type | Automatic | Manual |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 4 doors | 2 doors |
| Vehicle Weight | 1944 kg | 1895 kg |
| Vehicle Length | 5190 mm | 4830 mm |
| Vehicle Width | 1900 mm | 1860 mm |
| Vehicle Height | 1460 mm | 1380 mm |
| Wheelbase Size | 3080 mm | 2890 mm |
| Fuel Consumption Overall | 9.6 L/100km | 12.8 L/100km |
| Fuel Tank Capacity | 90 L | 70 L |
