Latest import data for key Asian countries and the US are beginning to show the impact of recent output cuts by Opec’s Gulf core. But whilst volumes are down from the record levels hit in the first quarter, they are still high by historical comparison. At least this is the case in volume terms – in terms of market share Gulf Opec is losing out in the fast-growing China market.

Saudi Arabia’s three biggest customers, Japan, China and the US all took substantially lower...