Should I switch to 10w-40 (Acea/E6) Or better stay with 5w-30 after removing DPF/egr delete and resofting my Jku 2009? Temepertures here: winter -15/-20 C ; summers: 30/40 C.
Ps: Overheating (>115-120C) problem solved by installing the solution from a German aftermarket producer:
https://mobile.allrad-pauli.de/index.php?id=232 (Expensive indeed but at least in my case solved the matter/ tested intensively last summer when it was verry hot and some times also very humid).