Maxx-Studio/Shutterstock Oil production by the 23-member alliance in August was 42 million barrels per day, flat compared to July.Output by the 13 core members of Opec rose by 120,000 b/d to 27.4 million b/d due mainly to increases from Iran, United Arab Emirates and Libya.Sources in Iran have confirmed an upswing in crude production of nearly 700,000 b/d from a dip in the first quarter. The shortfall for August was nearly 1.4 million b/d, slightly higher than July. Save for later Print Download Share LinkedIn Twitter Opec-plus’ performance last month featured a few sizable swings by individual producers, but for the group as a whole — whether the entire 23-member alliance or the 19 countries with a monthly quota — production was basically even with July.