2006 BMW 645 vs. 2007 Audi S4
To start off, 2007 Audi S4 is newer by 1 year(s). Which means there will be less support and parts availability for 2006 BMW 645. In addition, the cost of maintenance, including insurance, on 2006 BMW 645 would be higher. At 4,398 cc (8 cylinders), 2006 BMW 645 is equipped with a bigger engine. In terms of performance, 2007 Audi S4 (339 HP @ 7000 RPM) has 11 more horse power than 2006 BMW 645. (328 HP @ 6100 RPM) In normal driving conditions, 2007 Audi S4 should accelerate faster than 2006 BMW 645. With that said, vehicle weight also plays an important factor in acceleration. 2006 BMW 645 weights approximately 75 kg more than 2007 Audi S4.
Because 2007 Audi S4 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, 2007 Audi S4 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 40 more torque (in Nm) than 2007 Audi S4. (410 Nm @ 3500 RPM). This means 2006 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 2007 Audi S4.
Compare all specifications:
| 2006 BMW 645 | 2007 Audi S4 | |
| Make | BMW | Audi |
| Model | 645 | S4 |
| Year Released | 2006 | 2007 |
| Body Type | Coupe | Sedan |
| Engine Position | Front | Front |
| Engine Size | 4398 cc | 4163 cc |
| Engine Cylinders | 8 cylinders | 8 cylinders |
| Engine Type | V | V |
| Valves per Cylinder | 4 valves | 5 valves |
| Horse Power | 328 HP | 339 HP |
| Engine RPM | 6100 RPM | 7000 RPM |
| Torque | 450 Nm | 410 Nm |
| Torque RPM | 3600 RPM | 3500 RPM |
| Engine Compression Ratio | 10.0:1 | 11.0:1 |
| Fuel Type | Gasoline | Gasoline - Premium |
| Top Speed | 250 km/hour | 250 km/hour |
| Acceleration 0-100mph | 5.6 seconds | 5.9 seconds |
| Drive Type | Rear | 4WD |
| Transmission Type | Automatic | Automatic |
| Number of Seats | 4 seats | 5 seats |
| Number of Doors | 2 doors | 4 doors |
| Vehicle Weight | 1810 kg | 1735 kg |
| Vehicle Length | 4830 mm | 4580 mm |
| Vehicle Width | 1860 mm | 1790 mm |
| Vehicle Height | 1380 mm | 1420 mm |
| Wheelbase Size | 2790 mm | 2660 mm |
| Fuel Consumption Overall | 13.3 L/100km | 13.4 L/100km |
| Fuel Tank Capacity | 70 L | 63 L |
