If petrol, or pre-DPF Diesel, then oil to MB Spec Sheet 229.5.
If Diesel and DPF equipped, then oil to MB Spec Sheet 229.51, or better still, 229.52.
Viscosity should be either 5W-30, 5W-40, or 0W-40
Patrons oil is good, but you can also buy online cheap Mercedes-branded oil (which is probably produced by Petronas anyway).