The final version of the Roadster, the 4AD, was officially known as the Singer SM Roadster.
First seen at the October 1951 Paris Motor Show it was initially intended for export only.
It used the 48 hp (36 kW), 1497 cc engine from the SM1500 saloon fitted to a virtually unchanged chassis and body, retaining the hydraulic/mechanical hybrid braking system.
A 58 hp (43 kW) twin carburettor engine option was offered from 1953.
The 4AD can be told apart from a 4AB by its larger, rounder bumpers, as well as bigger taillights mounted on long stalks.

Although early 4AD production was still all for export, with the smaller 4AB being regularly available in the United Kingdom, from 1953 1.5 litre cars became available on the domestic market as well.

A car tested by The Motor magazine in 1951 had a top speed of 73 mph (117 km/h) and could accelerate from 0-60 mph (97 km/h) in 23.6 seconds.
A fuel consumption of 25.8 miles per imperial gallon (10.9 L/100 km; 21.5 mpg‑US) was recorded.
No price was quoted for the car as it was for export only.
The final version of the Roadster, the 4AD, was officially known as the Singer SM Roadster. First seen at the October 1951 Paris Motor Show it was initially intended for export only. It used the 48 hp (36 kW), 1497 cc engine from the SM1500 saloon fitted to a virtually unchanged chassis and body, retaining the hydraulic/mechanical hybrid braking system. A 58 hp (43 kW) twin carburettor engine option was offered from 1953. The 4AD can be told apart from a 4AB by its larger, rounder bumpers, as well as bigger taillights mounted on long stalks.
Although early 4AD production was still all for export, with the smaller 4AB being regularly available in the United Kingdom, from 1953 1.5 litre cars became available on the domestic market as well.
A car tested by The Motor magazine in 1951 had a top speed of 73 mph (117 km/h) and could accelerate from 0-60 mph (97 km/h) in 23.6 seconds. A fuel consumption of 25.8 miles per imperial gallon (10.9 L/100 km; 21.5 mpg‑US) was recorded. No price was quoted for the car as it was for export only.
Singer Roadster