Hello from Norway.
I joined the forum to learn a little about tuning. I have two cars at the moment. A 2005 BMW 525D with a shitty power box and a 2005 118d that seems to be tuned already.

I want to tune the 525d in a proper way, but the more I read about chip tuning, the more worried I get. I'm not comfortable uploading some random software to my engine without knowing what modifications and compromises has been done, therefore I want to learn how to do it myself.