Need to replace the thermostat on my 2010 E350. The last time I replaced it I seem to remember the operating temperature on the Wahler replacement was 89 degree. In shopping for a new one all I can fine are 100 degree replacements. Did Mbz change. My gauge would normally read around 90. The new one will read 100?

MB does improve the parts and I did have some parts that had 6 supersede numbers over just few years.
So if you are really doing your homework, find updated WIS and check what is last part applicable.
When it is probably not a big deal, you don't want to buy a part that local dealer put on shelf 4 years ago?