1986 BMW M5 vs. 1981 BMW 725
To start off, 1986 BMW M5 is newer by 5 year(s). Which means there will be less support and parts availability for 1981 BMW 725. In addition, the cost of maintenance, including insurance, on 1981 BMW 725 would be higher. At 3,428 cc (6 cylinders), 1986 BMW M5 is equipped with a bigger engine. In terms of performance, 1986 BMW M5 (218 HP @ 5200 RPM) has 70 more horse power than 1981 BMW 725. (148 HP @ 5500 RPM). In normal driving conditions, 1986 BMW M5 should accelerate faster than 1981 BMW 725.
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, 1986 BMW M5 (310 Nm @ 4000 RPM) has 95 more torque (in Nm) than 1981 BMW 725. (215 Nm @ 4000 RPM). This means 1986 BMW M5 will have an easier job in driving up hills or pulling heavy equipment than 1981 BMW 725.
Compare all specifications:
| 1986 BMW M5 | 1981 BMW 725 | |
| Make | BMW | BMW |
| Model | M5 | 725 |
| Year Released | 1986 | 1981 |
| Body Type | Sedan | Sedan |
| Engine Position | Front | Front |
| Engine Size | 3428 cc | 2493 cc |
| Engine Cylinders | 6 cylinders | 6 cylinders |
| Engine Type | in-line | in-line |
| Horse Power | 218 HP | 148 HP |
| Engine RPM | 5200 RPM | 5500 RPM |
| Torque | 310 Nm | 215 Nm |
| Torque RPM | 4000 RPM | 4000 RPM |
| Engine Bore Size | 92 mm | 86 mm |
| Engine Stroke Size | 86 mm | 71.6 mm |
| Engine Compression Ratio | 10.0:1 | 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 | 1300 mm | 1440 mm |
| Wheelbase Size | 2630 mm | 2810 mm |
