Strong demand for ultra-low sulfur diesel, combined with reduced global production, has resulted in U.S. diesel inventories, measured in days of supply, being at their lowest level since 2008. Moreover, U.S. refiners have increased diesel exports from 25% to 30% of domestic production to take advantage of higher foreign prices. Additionally, new global marine vessel emissions requirements have boosted diesel demand as they may no longer use dirtier bunker fuel.