1951 Alvis TB 21 vs. 1955 Armstrong Siddeley Sapphire
To start off, 1955 Armstrong Siddeley Sapphire is newer by 4 year(s). Which means there will be less support and parts availability for 1951 Alvis TB 21. In addition, the cost of maintenance, including insurance, on 1951 Alvis TB 21 would be higher. At 3,435 cc (6 cylinders), 1955 Armstrong Siddeley Sapphire is equipped with a bigger engine. In terms of performance, 1955 Armstrong Siddeley Sapphire (125 HP @ 4700 RPM) has 34 more horse power than 1951 Alvis TB 21. (91 HP @ 4000 RPM) In normal driving conditions, 1955 Armstrong Siddeley Sapphire should accelerate faster than 1951 Alvis TB 21.
Let's talk about torque, 1955 Armstrong Siddeley Sapphire (247 Nm) has 43 more torque (in Nm) than 1951 Alvis TB 21. (204 Nm). This means 1955 Armstrong Siddeley Sapphire will have an easier job in driving up hills or pulling heavy equipment than 1951 Alvis TB 21.
Compare all specifications:
| 1951 Alvis TB 21 | 1955 Armstrong Siddeley Sapphire | |
| Make | Alvis | Armstrong Siddeley |
| Model | TB 21 | Sapphire |
| Year Released | 1951 | 1955 |
| Engine Position | Front | Front |
| Engine Size | 2993 cc | 3435 cc |
| Engine Cylinders | 6 cylinders | 6 cylinders |
| Engine Type | in-line | in-line |
| Horse Power | 91 HP | 125 HP |
| Engine RPM | 4000 RPM | 4700 RPM |
| Torque | 204 Nm | 247 Nm |
| Engine Bore Size | 84 mm | 90 mm |
| Engine Stroke Size | 90 mm | 90 mm |
| Engine Compression Ratio | 7.1:1 | 7.0:1 |
| Number of Seats | 5 seats | 7 seats |
| Vehicle Length | 4430 mm | 5390 mm |
| Vehicle Width | 1680 mm | 1840 mm |
| Wheelbase Size | 2750 mm | 3380 mm |
