Tuesday marked the 1,000th consecutive day that average U.S. retail gasoline prices were above the $3.00 per gallon (3.8 liters) mark, motorist club AAA reported. AAA said the average retail price of a gallon of regular unleaded gasoline Tuesday was $3.51, about the same as a month ago but more than 30 cents cheaper than at the same time a year ago. Refiners use different additives in gasoline during the summer ozone season, which lasts from early June to mid-September. Winter-grade gasoline is cheaper to produce, meaning consumers can typically expect to pay less. AAA chief executive Bob Darbelnet said $3 gasoline likely will not be seen again. \"While a few lucky drivers may occasionally pay less than $3.00 per gallon, the national average is likely to remain more costly into the future,\" he said in a statement Monday. AAA said it expects the average retail price will remain above the $3 mark for the foreseeable future, barring another economic crash.