Have to purchase 5 single quarts or 5 quart jug . Wal-Mart has the 5 quart jugs for $22.66 ( $2.53 a qt. w/ $10 off ) and K-Mart has the quarts for $4.64 ( $2.64 a qt. w/ rebate ) . Wal-Mart may match the price of K-mart , needs to be within 30 miles of Wal-Mart . Go here for rebate ( http://www.pennzoil.com/promotions/ ) or this is attached to jugs at Wal_Mart . K-Mart also has Bosch synthetic filters for $7 and I think the Purolator Classic are $3 .