1974 Citroen SM vs. 1986 Renault 21
To start off, 1986 Renault 21 is newer by 12 year(s). Which means there will be less support and parts availability for 1974 Citroen SM. In addition, the cost of maintenance, including insurance, on 1974 Citroen SM would be higher. At 2,670 cc (6 cylinders), 1974 Citroen SM is equipped with a bigger engine. In terms of performance, 1974 Citroen SM (170 HP @ 5500 RPM) has 95 more horse power than 1986 Renault 21. (75 HP @ 5000 RPM). In normal driving conditions, 1974 Citroen SM should accelerate faster than 1986 Renault 21. With that said, vehicle weight also plays an important factor in acceleration. 1974 Citroen SM weights approximately 495 kg more than 1986 Renault 21. So despite on having greater horse power, its additional weight may have an impact towards its acceleration in comparison.
Both vehicles are front wheel drive (FWD). Which offers better traction when its slippery than rear 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, 1974 Citroen SM (237 Nm @ 4000 RPM) has 108 more torque (in Nm) than 1986 Renault 21. (129 Nm @ 3250 RPM). This means 1974 Citroen SM will have an easier job in driving up hills or pulling heavy equipment than 1986 Renault 21.
Compare all specifications:
| 1974 Citroen SM | 1986 Renault 21 | |
| Make | Citroen | Renault |
| Model | SM | 21 |
| Year Released | 1974 | 1986 |
| Engine Position | Front | Front |
| Engine Size | 2670 cc | 1719 cc |
| Engine Cylinders | 6 cylinders | 4 cylinders |
| Engine Type | V | in-line |
| Valves per Cylinder | 2 valves | 2 valves |
| Horse Power | 170 HP | 75 HP |
| Engine RPM | 5500 RPM | 5000 RPM |
| Torque | 237 Nm | 129 Nm |
| Torque RPM | 4000 RPM | 3250 RPM |
| Engine Bore Size | 87.1 mm | 81 mm |
| Engine Stroke Size | 75 mm | 83.5 mm |
| Fuel Type | Gasoline | Gasoline |
| Drive Type | Front | Front |
| Number of Seats | 2 seats | 5 seats |
| Number of Doors | 2 doors | 4 doors |
| Vehicle Weight | 1450 kg | 955 kg |
| Vehicle Length | 4900 mm | 4470 mm |
| Vehicle Width | 1850 mm | 1730 mm |
| Vehicle Height | 1330 mm | 1430 mm |
| Wheelbase Size | 2960 mm | 2550 mm |
| Fuel Tank Capacity | 25 L | 55 L |
