No. made : 3,827
Engine : 6-cylinder in-line configuration
Bore & stroke : 3 1/4" x 4 1/2"
Transmission : Single dry-plate type clutch, 4 speeds and reverse
Chassis : Pressed
steel, parallel girder with tubukar crossmembers,
semi-elliptic springs front and rear
Dimensions : Wheelbase 129"
Performance : Early
models max. speed 68 mph (109 km/h),
later models max. speed 76 mph (123 km/h)
The engine had a bigger bore which increased the capacity
to 3,669cc and
a higher compression ratio of 4.6:1
The 20/25 easily exceeded 60 mph and speeds in excess of
70mph could be acheived given a body with the right aero dynamics
The Engine still ran very quietly with the increase in power.
The 20/25 had an identical chassis to the later 20's which
were produced the
only difference being the larger capacity engine with the cross flow cylinder
Both the 20 and the 20/25 were made alongside each other during 1929.
A considerable improvement in roadholding
and passenger comfort was promoted by
modified shock absorbers, which were fitted from 1932 onwards. They didn't come up to
expectations completely, however, and in 1934 adjustable shock absorbers were fitted.
These permitted adjustment via a lever on the steering wheel and ensured appropriate
settings for low and high-speed drive conditions.
The series of "small" Rolls Royces
which had begun with the the Rolls-Royce 20 hp,
found a most successful continuation in the 20/25.
With a production figure of 3,827 this model turned out to have the highest sales in the
period between the wars.
The problem of high production costs
resulted in Rolls-Royce's first attempts to
In the past the purchase of parts from outside suppliers had been limited to electrical
components - and even then the company had laid down strict standards of quality.
In the last series of the 20/25 model, use was made for the first time of components from
independent suppliers for mechanical parts. Thus the clutch was supplied by Borg & Beck
and the steering box manufactured by Marles.These were clearly economy measures for Rolls-Royce.
Nevertheless, the suppliers charged higher prices to Rolls-Royce than to other car manufacturers
because of the short production runs involved - and Rolls-Royce could not be isolated from the
effects of asking suppliers for high quality standards.