An unexpectedly large drop in U.S. crude oil inventories is driving up the price of oil.

Benchmark oil gained 33 cents to $93.75 per barrel Wednesday in New York. Brent crude increased 97 cents to $115 per barrel in London.

The Energy Department says crude inventories fell 3.7 million barrels to 366.2 million barrels for the week ending Aug. 10. Analysts surveyed by Platts had predicted a decline of 1.5 million barrels.

Oil also is benefiting from an improvement in U.S. factory production in July. That could indicate stronger demand for oil and other energy products.

At the pump, the national average for gas is up less than a penny to $3.709 per gallon. That's about 31 cents more than a month ago.