does anyone know why there are huge price differences between oils? i was at midas the other day looking for a 15W-40 oil. just within the shell range, they have a shell helix (R280/5l) and a shell rimula (R175/5l). then midas have their own brand 15W-40 for R125/5l. why the huge price differences for a similar oil? or are there major differences?
