One motivation for the 230CE acquisition is to provide yet another platform for transmission development.

To illustrate, we use the Gear Speed app and plug in the data for the transmission used on the 230CE, the 722.122 aka W4B 025.
Here this stock configuration shows that at 75mph the engine is turning 3800 rpm.
Entertaining but very busy with high fuel consumption.


We also have in inventory the 16V auto transmission, a 722.410, with a faster first gear.


Now lets add an overdrive gear using the 5-speed manual from the W201 8V.
A very acceptable 2900@75mph.


6-speed manual borrowed from the R170 w/M111.
Note the higher numerics are returning 3100@75mph and making 1st a bit quick.
So ideally we would attempt longer diff gearing than the 3.58, and 3.27 seems appropriate.


Now we substitute a 6L45 6-spd auto, with its two overdrive gears, and see 2600 rpm at 75mph.


*** Footnotes ***
Redline for the M102.983 is set at 7000.
Don't expect much more than 125 in US trim, perhaps 130 after development.