1981 BMW 520 vs. 1984 BMW 725
To start off, 1984 BMW 725 is newer by 3 year(s). Which means there will be less support and parts availability for 1981 BMW 520. In addition, the cost of maintenance, including insurance, on 1981 BMW 520 would be higher. At 2,495 cc (6 cylinders), 1984 BMW 725 is equipped with a bigger engine. In terms of performance, 1984 BMW 725 (148 HP @ 5500 RPM) has 25 more horse power than 1981 BMW 520. (123 HP @ 5800 RPM) In normal driving conditions, 1984 BMW 725 should accelerate faster than 1981 BMW 520.
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, 1984 BMW 725 (215 Nm @ 4000 RPM) has 45 more torque (in Nm) than 1981 BMW 520. (170 Nm @ 4000 RPM). This means 1984 BMW 725 will have an easier job in driving up hills or pulling heavy equipment than 1981 BMW 520.
Compare all specifications:
| 1981 BMW 520 | 1984 BMW 725 | |
| Make | BMW | BMW |
| Model | 520 | 725 |
| Year Released | 1981 | 1984 |
| Body Type | Sedan | Sedan |
| Engine Position | Front | Front |
| Engine Size | 1991 cc | 2495 cc |
| Engine Cylinders | 6 cylinders | 6 cylinders |
| Engine Type | in-line | in-line |
| Horse Power | 123 HP | 148 HP |
| Engine RPM | 5800 RPM | 5500 RPM |
| Torque | 170 Nm | 215 Nm |
| Torque RPM | 4000 RPM | 4000 RPM |
| Engine Bore Size | 80 mm | 86 mm |
| Engine Stroke Size | 66 mm | 71.6 mm |
| Engine Compression Ratio | 9.8:1 | 9.6:1 |
| Drive Type | Rear | Rear |
| Number of Seats | 5 seats | 5 seats |
| Number of Doors | 4 doors | 4 doors |
| Vehicle Length | 4630 mm | 4870 mm |
| Vehicle Width | 1710 mm | 1810 mm |
| Vehicle Height | 1430 mm | 1440 mm |
| Wheelbase Size | 2630 mm | 2810 mm |
