mobil1 truck - 5w40 - the best out there for your engine - it also helps keep the EGR clean.
btw - what was the brand actually written on the bearing - the problem with febi is that they repackage other parts, previously they packaged nice stuff like INA, eff AG, NTN bearings - but now they are even packaging chinese garbage.
For rear bearings on this or infact any MB never cheap out - I usually buy it straight from the dealer because its a god damned labor intensive process to change them - the fronts are easy.