The reason I asked this question is I recently bought a W210 which has the gear with same shifting mechanism, d,4,3,2,1. The previous owner told me it is 4 speed auto whereas when i check the vin no it comes as 5 speed auto. as per wikipedia it is 5 speed auto.
When i am going at around 70km/h in D and shift the lever to 4, the RPM suddenly increases to around 25,000 and the car suddenly picks speed. It seems like a downshift to me. Technically if the gearbox is 4 speed, shifting from D to 4 should not make any difference. But there is a difference.
Can you please check on your car and share your experience ?