The Austin A50 Cambridge was introduced in conjunction with its sister car the A40 Cambridge in 1954 and was ostensibly no more than a larger-engined, more-powerful version of the A40.
Sharing all the same basic design, body-styling, running gear and suspension with the A40, the A50's engine was the definitive 1,489cc 50bhp version of the new B-Series design, and like the 1.2-litre version used on the A 40, it was equipped with a downdraught Zenith carburettor.
The  A50’s gearbox was also identical to the A40,  but because it was more powerful and more torquey than the  A40’s smaller engine, it was tuned to the higher final-drive ratio (4,875:1 instead of 5.125:1). 
Austin were obviously looking at the  A50 as a step up for better things to come and during the car’s production run introduced a number of  mechanical improvements.

These improvments included providing the option of fitting a Borg-Warner overdrive (available from early 1956), for the top three (of four) gears which BMC aligned to the 5.125:1 final drive of the A40.
This permutation was drawn from that which was already offered by Austin on their A90 Westminster.
To add to the driving experience, the overdrive could be transfigured so that it would cut-in automatically when the road speed exceeded 32mph, in either second, third or top gears.
As production of the Austin A50  Cambridge was beginning to wind down in 1956, BMC  surprisingly introduced a number of changes for the 1957 season.

These included fitting smaller, 13in road wheels as well as providing the option of Manumatic transmission (a form of two-pedal control).

It was later deduced by the motoring media that these developments were in actual fact to be BMC’s way of introducing new innovations “under the radar” for their Cambridge A55 model which was introduced the following year.

As had been widely predicted in the motoring media, production of the Austin A50 Cambridge was discontinued in 1957 with the immediate launch of the A55 model, which was, in fact, a re-engineered version of the A50 itself.