E500 2004 4matic wagon winter tires
 

I am looking to buy winter tires for my wagon and I feel like the originals are too wide. 245/45 17 = 25.68 inches
After I used the online tire calculator I realized that
225/50 17 = 25.86 inches is not that farr off ....only 0.18 in outside circ.
Can this be such a big issue on this car. I am aware that my E500 comes with a lot of sensitive electronics. Will they suffer if I am changing to this 225/50 17 tire?

That's the factory (staggered) tire size that Mercedes decided on. Not sure why you'd want to mess with that kind of R&D. While 225/50 might work, I don't know if that would fit on your 8.5" wide rear wheel properly?

My advice, either stick with 245/45 in the rear or get some non-staggered wheels and run 225's all around.

What I was trying to say is that 245 tires are harder to control than 225 in a 6-8 inch of north east snow from november til april.
A lot of MB owners in europe are using reduced sizes on the winter tires.
What I am asking is that by changing all four tires from 245/45 to 225/50 will be something my can can't handle?

All four of your wheels and tires are the same size, yes?

I think your other reply for some reason thinks they are staggered.

If they are all the same size, then yes, absolutely, you can use 225/50-17.

Safe travels!