Some semi synth brands:
Mobil super S 10w40- about P250/L
Castrol Magnatec 10w40- about P230/L
Top1 20w50- about P220/L
IMO, go full synth or plain mineral oil.
You save about 25% if you buy in bulk, ie, a box of 12L or 6x4L from an oil distributor.