The average U.S. price for gasoline dropped below $2 a gallon on Monday for the first time in five weeks, the government said.

The national price for regular unleaded gasoline fell 4.9 cents over the last week to $1.985 a gallon, according to a weekly survey of gasoline stations by the Energy Information Administration (search).

But the EIA, which is the Energy Department's (search) analytical arm, said the average pump price is still 47 cents a gallon higher than a year ago.

Drivers have enjoyed an 8 cent drop for gasoline over the last three weeks from the record high price of $2.06 a gallon.

The savings at the pump are the result of declining crude oil prices, which account for almost half the cost of making gasoline.

OPEC (search) has promised to send more oil tankers to the U.S. market to replenish supplies and lower petroleum prices.

Separately, the EIA survey said the average pump price for diesel fuel dropped 2.3 cents to $1.711 a gallon, but up 28 cents from a year ago.

Truckers on the West Coast paid the most for diesel fuel at $1.998 a gallon, down 6.5 cents from the prior week. The Gulf Coast states had the cheapest diesel at $1.635 a gallon, off 2 cents.