emil67

How often is it recommended to change the transmission fluid in a 2012 E350 Blue Tech

S430AMG

You are in the wrong forum. In general I service transmission fluid/filter around 60-100k on all my cars. I usually drain the fluid once and refill, before I do it again and replace filter/gasket just to let the new fluid mix with what's in there before I replace the filter. But it varies depending on reliability and usage of each transmission.