1961 AC Ace vs. 1973 Citroen SM
To start off, 1973 Citroen SM is newer by 12 year(s). Which means there will be less support and parts availability for 1961 AC Ace. In addition, the cost of maintenance, including insurance, on 1961 AC Ace would be higher. At 2,670 cc (6 cylinders), 1973 Citroen SM is equipped with a bigger engine. In terms of performance, 1973 Citroen SM (171 HP @ 5500 RPM) has 71 more horse power than 1961 AC Ace. (100 HP @ 5500 RPM) In normal driving conditions, 1973 Citroen SM should accelerate faster than 1961 AC Ace. With that said, vehicle weight also plays an important factor in acceleration. 1973 Citroen SM weights approximately 637 kg more than 1961 AC Ace. So despite on having greater horse power, its additional weight may have an impact towards its acceleration in comparison.
Because 1961 AC Ace is rear wheel drive (RWD), it offers better handling in dry conditions; in addition, if you are looking to drift, it will be much easier to do with 1961 AC Ace. However, in wet, icy, snow, or gravel driving conditions, 1973 Citroen SM, being front wheel drive (FWD), will offer much better control with better grip. 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, 1973 Citroen SM (237 Nm @ 4000 RPM) has 57 more torque (in Nm) than 1961 AC Ace. (180 Nm @ 2000 RPM). This means 1973 Citroen SM will have an easier job in driving up hills or pulling heavy equipment than 1961 AC Ace.
Compare all specifications:
| 1961 AC Ace | 1973 Citroen SM | |
| Make | AC | Citroen |
| Model | Ace | SM |
| Year Released | 1961 | 1973 |
| Body Type | Roadster | Coupe |
| Engine Position | Front | Front |
| Engine Size | 2553 cc | 2670 cc |
| Engine Cylinders | 6 cylinders | 6 cylinders |
| Engine Type | in-line | V |
| Horse Power | 100 HP | 171 HP |
| Engine RPM | 5500 RPM | 5500 RPM |
| Torque | 180 Nm | 237 Nm |
| Torque RPM | 2000 RPM | 4000 RPM |
| Engine Bore Size | 82.6 mm | 87 mm |
| Engine Stroke Size | 79.5 mm | 75 mm |
| Engine Compression Ratio | 7.8:1 | 9.0:1 |
| Drive Type | Rear | Front |
| Number of Seats | 2 seats | 2 seats |
| Number of Doors | 2 doors | 2 doors |
| Vehicle Weight | 813 kg | 1450 kg |
| Vehicle Length | 3860 mm | 4900 mm |
| Vehicle Width | 1490 mm | 1850 mm |
| Vehicle Height | 1250 mm | 1330 mm |
| Wheelbase Size | 2290 mm | 2960 mm |
| Fuel Tank Capacity | 54 L | 25 L |
