2004 BMW Z4 vs. 2006 Fiat Siena
To start off, 2006 Fiat Siena is newer by 2 year(s). Which means there will be less support and parts availability for 2004 BMW Z4. In addition, the cost of maintenance, including insurance, on 2004 BMW Z4 would be higher. At 2,494 cc (6 cylinders), 2004 BMW Z4 is equipped with a bigger engine. In terms of performance, 2004 BMW Z4 (185 HP @ 6000 RPM) has 84 more horse power than 2006 Fiat Siena. (101 HP @ 5500 RPM). In normal driving conditions, 2004 BMW Z4 should accelerate faster than 2006 Fiat Siena. With that said, vehicle weight also plays an important factor in acceleration. 2006 Fiat Siena weights approximately 487 kg more than 2004 BMW Z4.
Because 2004 BMW Z4 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 2004 BMW Z4. However, in wet, icy, snow, or gravel driving conditions, 2006 Fiat Siena, 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, 2004 BMW Z4 (245 Nm @ 3500 RPM) has 105 more torque (in Nm) than 2006 Fiat Siena. (140 Nm @ 4000 RPM). This means 2004 BMW Z4 will have an easier job in driving up hills or pulling heavy equipment than 2006 Fiat Siena.
Compare all specifications:
| 2004 BMW Z4 | 2006 Fiat Siena | |
| Make | BMW | Fiat |
| Model | Z4 | Siena |
| Year Released | 2004 | 2006 |
| Body Type | Convertible | Sedan |
| Engine Position | Front | Front |
| Engine Size | 2494 cc | 1581 cc |
| Engine Cylinders | 6 cylinders | 4 cylinders |
| Engine Type | in-line | in-line |
| Valves per Cylinder | 4 valves | 2 valves |
| Horse Power | 185 HP | 101 HP |
| Engine RPM | 6000 RPM | 5500 RPM |
| Torque | 245 Nm | 140 Nm |
| Torque RPM | 3500 RPM | 4000 RPM |
| Engine Bore Size | 84 mm | 86.4 mm |
| Engine Stroke Size | 75 mm | 67.4 mm |
| Engine Compression Ratio | 11.0:1 | 9.5:1 |
| Top Speed | 235 km/hour | 184 km/hour |
| Drive Type | Rear | Front |
| Transmission Type | Manual | Manual |
| Number of Seats | 2 seats | 5 seats |
| Number of Doors | 2 doors | 4 doors |
| Vehicle Weight | 1296 kg | 1783 kg |
| Vehicle Length | 4100 mm | 3830 mm |
| Vehicle Width | 1790 mm | 1640 mm |
| Vehicle Height | 1300 mm | 1440 mm |
| Wheelbase Size | 2500 mm | 2380 mm |
| Fuel Consumption Overall | 10.2 L/100km | 8 L/100km |
| Fuel Tank Capacity | 55 L | 54 L |
