Note: This is a sub-section of Riley: Cars.
- RMA. 1945-52. 10,504 made. The RMA was a large saloon, and was replaced by the RME.
- RMB. 1946-52. 6,900 made. The RMB was an even larger car, and was replaced by the RMF.
- RMC. 1948-51. 507 made. The RMC and RMD were limited-production roadsters.
- RMD. 1949-51. 502 made. The RMC and RMD were limited-production roadsters.
- RME. 1952-55. 3,446 made. See RMA.
- RMF. 1952-53. 1,050 made. See RMB.
The Riley RM Series was the last automobile series developed independently by Riley. RM vehicles were produced from 1945, after World War II, through the 1952 merger of the Riley's Nuffield Organisation with Austin to form BMC.
They were originally made in Coventry but in 1949 production moved to the MG works at Abingdon.
All of the RM vehicles featured the pre-war Riley designed 1.5 L (1496 cc) 12 hp (RAC Rating) or 16 hp (RAC Rating) 2.5 L "Big Four" straight-4 engines with twin camshafts mounted high at the sides of the cylinder block and hemispherical combustion chambers.
The RMA was the first post-war Riley. It used the 1.5 Litre engine and was equipped with hydro-mechanical brakes and an independent suspension using torsion bars in front. The frame was made of wood in the English tradition, and the car featured traditional styling. The car was capable of reaching 75 mph. The RMA was produced from 1945 until 1952 when it was replaced by the RME.
The RMB was an enlarged RMA and was launched a year later in 1946. It used the 2.5 Litre "Big Four" engine with twin SU carburettors, starting with 90 hp but increasing to 100 hp for 1948 with a 95 mph top speed. The RMB was replaced by the RMF for 1952.
The RMC was a 3-passenger 2-door convertible version of the RMB with a large rear deck area and fold flat windscreen. It shared that car's 2.5 Litre 100 hp engine and could reach 100 mph. The car was primarily designed for the North American export market, and just over 500 were built from 1948 until 1951. The gear change lever was moved to the steering column on left hand drive models.
The RMD was a traditional 2-door drophead coupé, the last convertible to wear the Riley name. It used the same 2.5 L 100 hp (75 kW) engine as the RMB, on which it was based. Just over 500 were produced between 1949 and 1951.
The RME was an updated RMA. It still used the 1.5 Litre four and featured a fully-hydraulic braking system. The body had an enlarged rear window with curved glass and from 1954 no running boards. To improve acceleration the rear axle ratio was changed from 4.89:1 to 5.125:1. Produced from 1952, it was replaced by the Riley One-Point-Five in 1955.
The RMF replaced the big RMB limousine in 1952. It shared that car's 2.5 Litre "Big Four" engine as well as the mechanical updates from the RME. The RMH Riley Pathfinder, last of the Riley "Big Fours", and thus the last real Riley, took its place after 1953 and continued in production until 1957.
Sources of Information
-  Wikipedia