2009 Audi A4 vs. 2008 BMW 645
To start off, 2009 Audi A4 is newer by 1 year(s). Which means there will be less support and parts availability for 2008 BMW 645. In addition, the cost of maintenance, including insurance, on 2008 BMW 645 would be higher. At 4,398 cc (8 cylinders), 2008 BMW 645 is equipped with a bigger engine. In terms of performance, 2008 BMW 645 (328 HP @ 6100 RPM) has 170 more horse power than 2009 Audi A4. (158 HP @ 4500 RPM) In normal driving conditions, 2008 BMW 645 should accelerate faster than 2009 Audi A4. With that said, vehicle weight also plays an important factor in acceleration. 2008 BMW 645 weights approximately 760 kg more than 2009 Audi A4. So despite on having greater horse power, its additional weight may have an impact towards its acceleration in comparison.
Because 2008 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 2008 BMW 645. However, in wet, icy, snow, or gravel driving conditions, 2009 Audi A4, 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 BMW 645 (450 Nm @ 3600 RPM) has 200 more torque (in Nm) than 2009 Audi A4. (250 Nm @ 1500 RPM). This means 2008 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 2009 Audi A4.
Compare all specifications:
| 2009 Audi A4 | 2008 BMW 645 | |
| Make | Audi | BMW |
| Model | A4 | 645 |
| Year Released | 2009 | 2008 |
| Body Type | Sedan | Coupe |
| Engine Position | Front | Front |
| Engine Size | 1798 cc | 4398 cc |
| Engine Cylinders | 4 cylinders | 8 cylinders |
| Engine Type | in-line | V |
| Valves per Cylinder | 4 valves | 4 valves |
| Horse Power | 158 HP | 328 HP |
| Engine RPM | 4500 RPM | 6100 RPM |
| Torque | 250 Nm | 450 Nm |
| Torque RPM | 1500 RPM | 3600 RPM |
| Engine Bore Size | 82.5 mm | 92.1 mm |
| Engine Stroke Size | 84.1 mm | 82.7 mm |
| Engine Compression Ratio | 9.6:1 | 10.0:1 |
| Fuel Type | Gasoline - Premium | Gasoline - Premium |
| Acceleration 0-100mph | 8.9 seconds | 5.6 seconds |
| Drive Type | Front | Rear |
| Transmission Type | Automatic | Automatic |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 4 doors | 2 doors |
| Vehicle Weight | 930 kg | 1690 kg |
| Vehicle Length | 4710 mm | 4830 mm |
| Vehicle Width | 2010 mm | 1860 mm |
| Vehicle Height | 1430 mm | 1380 mm |
| Wheelbase Size | 2810 mm | 2790 mm |
| Fuel Consumption Overall | 7.4 L/100km | 11.8 L/100km |
| Fuel Tank Capacity | 65 L | 70 L |
