1999 Audi A4 vs. 2006 BMW 645
To start off, 2006 BMW 645 is newer by 7 year(s). Which means there will be less support and parts availability for 1999 Audi A4. In addition, the cost of maintenance, including insurance, on 1999 Audi A4 would be higher. At 4,398 cc (8 cylinders), 2006 BMW 645 is equipped with a bigger engine. In terms of performance, 2006 BMW 645 (328 HP @ 6100 RPM) has 205 more horse power than 1999 Audi A4. (123 HP @ 5800 RPM) In normal driving conditions, 2006 BMW 645 should accelerate faster than 1999 Audi A4. With that said, vehicle weight also plays an important factor in acceleration. 2006 BMW 645 weights approximately 480 kg more than 1999 Audi A4. So despite on having greater horse power, its additional weight may have an impact towards its acceleration in comparison.
Because 1999 Audi A4 is four wheel drive (4WD), it will have significant more traction and grip than 2006 BMW 645. In wet, icy, snow, or gravel driving conditions, 1999 Audi A4 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, 2006 BMW 645 (450 Nm @ 3600 RPM) has 282 more torque (in Nm) than 1999 Audi A4. (168 Nm @ 3500 RPM). This means 2006 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 1999 Audi A4.
Compare all specifications:
| 1999 Audi A4 | 2006 BMW 645 | |
| Make | Audi | BMW |
| Model | A4 | 645 |
| Year Released | 1999 | 2006 |
| Body Type | Sedan | Convertible |
| Engine Position | Front | Front |
| Engine Size | 1781 cc | 4398 cc |
| Engine Cylinders | 4 cylinders | 8 cylinders |
| Engine Type | in-line | V |
| Horse Power | 123 HP | 328 HP |
| Engine RPM | 5800 RPM | 6100 RPM |
| Torque | 168 Nm | 450 Nm |
| Torque RPM | 3500 RPM | 3600 RPM |
| Engine Bore Size | 81 mm | 92 mm |
| Engine Stroke Size | 86.4 mm | 83 mm |
| Engine Compression Ratio | 10.3:1 | 10.0:1 |
| Top Speed | 201 km/hour | 250 km/hour |
| Acceleration 0-100mph | 11 seconds | 6.1 seconds |
| Drive Type | 4WD | Rear |
| Transmission Type | Manual | Manual |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 4 doors | 2 doors |
| Vehicle Weight | 1356 kg | 1836 kg |
| Vehicle Length | 4480 mm | 4830 mm |
| Vehicle Width | 1740 mm | 1860 mm |
| Vehicle Height | 1420 mm | 1380 mm |
| Wheelbase Size | 2610 mm | 2790 mm |
| Fuel Tank Capacity | 60 L | 70 L |
