2005 BMW 645 vs. 2011 BMW Z4
To start off, 2011 BMW Z4 is newer by 6 year(s). Which means there will be less support and parts availability for 2005 BMW 645. In addition, the cost of maintenance, including insurance, on 2005 BMW 645 would be higher. At 4,392 cc (8 cylinders), 2005 BMW 645 is equipped with a bigger engine. In terms of performance, 2011 BMW Z4 (335 HP @ 5900 RPM) has 9 more horse power than 2005 BMW 645. (326 HP @ 6100 RPM) In normal driving conditions, 2011 BMW Z4 should accelerate faster than 2005 BMW 645. With that said, vehicle weight also plays an important factor in acceleration. 2005 BMW 645 weights approximately 285 kg more than 2011 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, 2011 BMW Z4 (450 Nm @ 1500 RPM) has 3 more torque (in Nm) than 2005 BMW 645. (447 Nm @ 3600 RPM). This means 2011 BMW Z4 will have an easier job in driving up hills or pulling heavy equipment than 2005 BMW 645. 2011 BMW Z4 has automatic transmission and 2005 BMW 645 has manual transmission. 2005 BMW 645 will offer better control over acceleration and deceleration in addition to better fuel efficiency overall. 2011 BMW Z4 will be easier to drive especially in heavy traffic.
Compare all specifications:
| 2005 BMW 645 | 2011 BMW Z4 | |
| Make | BMW | BMW |
| Model | 645 | Z4 |
| Year Released | 2005 | 2011 |
| Body Type | Convertible | Convertible |
| Engine Position | Front | Front |
| Engine Size | 4392 cc | 3000 cc |
| Engine Cylinders | 8 cylinders | 6 cylinders |
| Engine Type | V | in-line |
| Valves per Cylinder | 4 valves | 4 valves |
| Horse Power | 326 HP | 335 HP |
| Engine RPM | 6100 RPM | 5900 RPM |
| Torque | 447 Nm | 450 Nm |
| Torque RPM | 3600 RPM | 1500 RPM |
| Fuel Type | Gasoline - Premium | Gasoline |
| Drive Type | Rear | Rear |
| Transmission Type | Manual | 7-speed automated manual |
| Number of Seats | 4 seats | 2 seats |
| Number of Doors | 2 doors | 2 doors |
| Vehicle Weight | 1895 kg | 1610 kg |
| Vehicle Length | 4830 mm | 4242 mm |
| Vehicle Width | 1860 mm | 1791 mm |
| Vehicle Height | 1380 mm | 1285 mm |
| Wheelbase Size | 2890 mm | 2497 mm |
| Fuel Consumption Highway | 10.2 L/100km | 9.8 L/100km |
| Fuel Consumption City | 15.7 L/100km | 13.8 L/100km |
| Fuel Tank Capacity | 70 L | 55 L |
