1991 Buick Roadmaster vs. 2005 BMW 645
To start off, 2005 BMW 645 is newer by 14 year(s). Which means there will be less support and parts availability for 1991 Buick Roadmaster. In addition, the cost of maintenance, including insurance, on 1991 Buick Roadmaster would be higher. At 5,731 cc (8 cylinders), 1991 Buick Roadmaster is equipped with a bigger engine. In terms of performance, 2005 BMW 645 (326 HP @ 6100 RPM) has 149 more horse power than 1991 Buick Roadmaster. (177 HP @ 4200 RPM) In normal driving conditions, 2005 BMW 645 should accelerate faster than 1991 Buick Roadmaster. With that said, vehicle weight also plays an important factor in acceleration. 2005 BMW 645 weights approximately 55 kg more than 1991 Buick Roadmaster. So despite on having greater horse power, its additional weight may have an impact towards its acceleration in comparison.
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, 2005 BMW 645 (447 Nm @ 3600 RPM) has 54 more torque (in Nm) than 1991 Buick Roadmaster. (393 Nm @ 2400 RPM). This means 2005 BMW 645 will have an easier job in driving up hills or pulling heavy equipment than 1991 Buick Roadmaster.
Compare all specifications:
| 1991 Buick Roadmaster | 2005 BMW 645 | |
| Make | Buick | BMW |
| Model | Roadmaster | 645 |
| Year Released | 1991 | 2005 |
| Body Type | Sedan | Convertible |
| Engine Position | Front | Front |
| Engine Size | 5731 cc | 4392 cc |
| Engine Cylinders | 8 cylinders | 8 cylinders |
| Engine Type | V | V |
| Horse Power | 177 HP | 326 HP |
| Engine RPM | 4200 RPM | 6100 RPM |
| Torque | 393 Nm | 447 Nm |
| Torque RPM | 2400 RPM | 3600 RPM |
| Engine Compression Ratio | 8.0:1 | 10.5:1 |
| Fuel Type | Gasoline | Gasoline - Premium |
| Drive Type | Rear | Rear |
| Transmission Type | Automatic | Automatic |
| Number of Seats | 5 seats | 4 seats |
| Number of Doors | 4 doors | 2 doors |
| Vehicle Weight | 1840 kg | 1895 kg |
| Vehicle Length | 5280 mm | 4830 mm |
| Vehicle Width | 2040 mm | 1860 mm |
| Vehicle Height | 1650 mm | 1380 mm |
| Wheelbase Size | 2950 mm | 2890 mm |
| Fuel Tank Capacity | 75 L | 70 L |
