(Bloomberg) --For a sneak peek at the return of Chinese oil demand, look no further than the rebound in price of the nation’s favorite grades.

In the last few days a Chinese state-owned refiner bought Brazil’s Lula crude for August arrival at a premium of about 50 cents a barrel to Brent on a delivered basis, according to four traders in Asia. That’s a sharp recovery from the middle of April when the same grade traded at a discount of around $6.

The price jump comes as factories across Asia’s largest economy restart and people return to work, with some favoring their cars over taking public transport. Crude processing at China’s independent refineries is now higher than pre-virus levels, while fuel demand is also starting to rebound in India.

Output curbs by the OPEC+ alliance have led to steep increases in official selling prices by producers including Saudi Arabia and Kuwait. Supplies of Basrah oil from Iraq were also cut to at least three Asian buyers for June this week, tightening regional balances. That, in turn, is prompting marketers of crude from the Americas to Africa to hike offer levels in Asia, despite ample inventories in onshore and floating storage.

Offers for Lula into China have been as high as a $2 premium to Brent in recent days, the traders said, while an independent refiner paid more for Congo’s Djeno oil than it did a few weeks ago. Oman crude, a popular grade in China, has surged to the equivalent of a $2 premium to Dubai swaps on the Dubai Mercantile Exchange Wednesday from a discount of more than $6 in mid-April.

However, the rebound may be hard to sustain without a continued recovery in refining margins and a drawdown of fuel inventories, some of the traders said. Returns from turning crude into fuel in Singapore turned positive this week, but profits are about $3 a barrel under the five-year average for this time of the year, data from Oil Analytics show. Fuel inventories at the Asian oil hub haven’t receded that much from April when they rose to the highest since 2016.