2006 BMW Z4 vs. 2003 BMW 320
To start off, 2006 BMW Z4 is newer by 3 year(s). Which means there will be less support and parts availability for 2003 BMW 320. In addition, the cost of maintenance, including insurance, on 2003 BMW 320 would be higher. At 2,492 cc (6 cylinders), 2006 BMW Z4 is equipped with a bigger engine. In terms of performance, 2006 BMW Z4 (189 HP @ 6000 RPM) has 41 more horse power than 2003 BMW 320. (148 HP @ 5900 RPM). In normal driving conditions, 2006 BMW Z4 should accelerate faster than 2003 BMW 320. With that said, vehicle weight also plays an important factor in acceleration. 2003 BMW 320 weights approximately 130 kg more than 2006 BMW Z4.
Both vehicles are rear wheel drive (RWD) - it offers better handling in dry conditions; in addition, if you are looking to drift, both vehicles do the job better than front wheel drive vehicles. 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 Z4 (245 Nm @ 3500 RPM) has 35 more torque (in Nm) than 2003 BMW 320. (210 Nm @ 3750 RPM). This means 2006 BMW Z4 will have an easier job in driving up hills or pulling heavy equipment than 2003 BMW 320.
Compare all specifications:
| 2006 BMW Z4 | 2003 BMW 320 | |
| Make | BMW | BMW |
| Model | Z4 | 320 |
| Year Released | 2006 | 2003 |
| Body Type | Convertible | Convertible |
| Engine Position | Front | Front |
| Engine Size | 2492 cc | 1995 cc |
| Engine Cylinders | 6 cylinders | 4 cylinders |
| Engine Type | in-line | in-line |
| Valves per Cylinder | 4 valves | 4 valves |
| Horse Power | 189 HP | 148 HP |
| Engine RPM | 6000 RPM | 5900 RPM |
| Torque | 245 Nm | 210 Nm |
| Torque RPM | 3500 RPM | 3750 RPM |
| Engine Bore Size | 84 mm | 84 mm |
| Engine Stroke Size | 75 mm | 90 mm |
| Engine Compression Ratio | 11.0:1 | 10.0:1 |
| Fuel Type | Gasoline - Premium | Gasoline - Premium |
| Drive Type | Rear | Rear |
| Transmission Type | Manual | Manual |
| Number of Seats | 2 seats | 4 seats |
| Number of Doors | 2 doors | 2 doors |
| Vehicle Weight | 1335 kg | 1465 kg |
| Vehicle Length | 4100 mm | 4490 mm |
| Vehicle Width | 1790 mm | 1760 mm |
| Vehicle Height | 1310 mm | 1380 mm |
| Wheelbase Size | 2500 mm | 2730 mm |
| Fuel Tank Capacity | 55 L | 63 L |
