| MODEL | ARIEL 4G SQUARE FOUR MARK II 1957 |
| Year | 1957 |
| Engine Type | Square four, OHV |
| Displacement / Capacity | 995 cc |
| Bore X Stroke | 65 x 78 mm / 2.56 x 3.07 in |
| Compression Ratio | 6:1 |
| Cooling System | Air |
| Max Power | 33.6 kW / 45 hp @ 5500 rpm |
| Max Torque | — |
| Ignition | — |
| Induction | Carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 4-speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | — |
| Rear Suspension | — |
| Front Brakes | Expanding brake (drum), 178 mm / 7 in |
| Rear Brakes | Expanding brake (drum), 203 mm / 8 in |
| DIMENSION SPECS | |
| Overall Length | 2184 mm / 86 in |
| Overall Width | 685 mm / 27 in |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | 1422 mm / 56 in |
| Ground Clearance | 139 mm / 5.5 in |
| Dry Weight | — |
| Wet Weight | 197.3 kg / 435 lb |
| WHEEL SPECS | |
| Front Tyre | 3.25-19 |
| Rear Tyre | 4.00-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 18.9 Litres / 5.0 US gal |
| Fuel Consumption | 3.04 L/100 km |
| Top Speed | 160 km/h / 99.4 mph |
The Mark II Square Four moved to an aluminium-alloy cylinder block and head, giving a lighter, cooler-running 995 cc four with more power than the Mark I. It remained a refined, flexible sporting tourer that was among the fastest British roadsters of its day.
