2005 Audi A4 vs. 1981 BMW 518
To start off, 2005 Audi A4 is newer by 24 year(s). Which means there will be less support and parts availability for 1981 BMW 518. In addition, the cost of maintenance, including insurance, on 1981 BMW 518 would be higher. At 1,781 cc (4 cylinders), 2005 Audi A4 is equipped with a bigger engine. In terms of performance, 2005 Audi A4 (180 HP @ 5700 RPM) has 90 more horse power than 1981 BMW 518. (90 HP @ 5500 RPM). In normal driving conditions, 2005 Audi A4 should accelerate faster than 1981 BMW 518. With that said, vehicle weight also plays an important factor in acceleration. 2005 Audi A4 weights approximately 335 kg more than 1981 BMW 518. So despite on having greater horse power, its additional weight may have an impact towards its acceleration in comparison.
Because 2005 Audi A4 is four wheel drive (4WD), it will have significant more traction and grip than 1981 BMW 518. In wet, icy, snow, or gravel driving conditions, 2005 Audi A4 will offer significantly more control. 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 Audi A4 (240 Nm @ 1950 RPM) has 100 more torque (in Nm) than 1981 BMW 518. (140 Nm @ 4000 RPM). This means 2005 Audi A4 will have an easier job in driving up hills or pulling heavy equipment than 1981 BMW 518.
Compare all specifications:
| 2005 Audi A4 | 1981 BMW 518 | |
| Make | Audi | BMW |
| Model | A4 | 518 |
| Year Released | 2005 | 1981 |
| Body Type | Sedan | Sedan |
| Engine Position | Front | Front |
| Engine Size | 1781 cc | 1766 cc |
| Engine Cylinders | 4 cylinders | 4 cylinders |
| Engine Type | in-line | in-line |
| Horse Power | 180 HP | 90 HP |
| Engine RPM | 5700 RPM | 5500 RPM |
| Torque | 240 Nm | 140 Nm |
| Torque RPM | 1950 RPM | 4000 RPM |
| Engine Bore Size | 81 mm | 89 mm |
| Engine Stroke Size | 86.4 mm | 71.1 mm |
| Engine Compression Ratio | 9.3:1 | 9.5:1 |
| Drive Type | 4WD | Rear |
| Transmission Type | Manual | Manual |
| Number of Seats | 5 seats | 5 seats |
| Number of Doors | 4 doors | 4 doors |
| Vehicle Weight | 1475 kg | 1140 kg |
| Vehicle Length | 4550 mm | 4630 mm |
| Vehicle Width | 1770 mm | 1710 mm |
| Vehicle Height | 1430 mm | 1430 mm |
| Wheelbase Size | 2660 mm | 2630 mm |
