Average gasoline demand in the week to Aug. 12 fell 4.6 percent year-on-year, though it rose slightly — by 0.3 percent — from the previous week, the data showed.

Over the latest four weeks, average US gasoline consumption fell 3.4 percent from year-earlier levels, its 21st straight decline.

The average price of gasoline fell 7 cents to $3.63 a gallon last week from the week before, as dipping futures prices translated into cheaper fuel at the pump.

Prices, however, were 31.5 percent higher than a year earlier, MasterCard said.

MasterCard Advisers, a unit of MasterCard, estimates retail gasoline demand based on aggregate sales in the MasterCard payments system coupled with estimates for other payment forms including cash and checks.