How many miles are on your original DPF/SCR?

[Firebird]

I'm trying to get a feel for how long the original stock system may last, as I know they are stupid expensive to replace.
So, how many miles on your system?
How do you mainly drive, city, hwy?
Do you use any additives?

 

[Jacob]

I'm at 37k miles. I'm probably evenly divided: towing highway, highway, city. No emission system issues and I'm not into additives.